bulletproof FindCurve/Surface + uniformize error messages

create the default project file in the home directory if no "current"
directory is defined (e.g. when double-clicking on the icon on Windows/MacOS)

add @. after color specs in Fl_Browser: otherwise strings that start
with a digit don't get printed

- set VectorType to Displacement in Plugin(StreamLines)
- shout when a plugin option/name does not exist

new BoundingBox command to force the computation of the bounding box (useful
when there is no geometry and we don't include/merge any views)

- generalized vertex arrays to handle quads

- added missing Ellispe ... Plane ... in parser

- generalized vertex array class to use reallocatable arrays

- introduced vertex arrays in post for all triangles: this speeds
  things up tremendously for ALL scalar views: 2d scalar views of
  course, but also for 3d isos (tets, hexas, etc.) and all smooth
  normals. The costly computations (compute the isos, get the normals)
  are only done ONCE each time the view is changed. Then we just pass
  the vertex array to OpenGL everytime we need to redraw (e.g. when we
  rotate the scene)

- removed the display list code alltogether: it's completely blown
  away by the new vertex array code!

for the record: with the new drawing code, you can

- rotate 500,000 triangles in real time on a 3-year old linux PC
(tested with a boing 747 surface mesh from CU: 10 times faster than
old code)

- display and rotate in real time 10 transparent+smooth shaded 3D isos
for a 1 million tet mesh (about 1 frame per second with the new code;
took tens of seconds with the old one)

Awesome :-)

Added final bit for 2nd order elements: the middle face nodes for
quadrangular faces (i.e., for quadrangles, hexahedra, prisms and
pyramids).

- removed the quads from the simplex trees (finally...)

  **warning**

  this is a pretty big patch that touches a lot of different files. I
  tried my best to update all the things that needed to be updated,
  but I probably forgot some things... Please test! (especially the
  export routines in obscure formats like SMS, Gref, etc., as well as
  the extrusion code)

- added second order edge vertices for hexas, prisms and pyramids
  (drawing not done yet)

- added sanity check for number of values in post-pro parsed file
  format

- merged all mesh printing/reading routines in Print_Mesh.cpp and
  Read_Mesh.cpp

- cleaned up the statistics code

make parser

Small changes inspired by Wednesday's discussions:

- added FL::check in redraw_opengl() (and thus removed DrawUI()):
  this should (?) fix the missing redraws

- protected the orientation calculation with a lock

- made the mode selection widget do its callback even if we don't
  change the selection (so that we always go back to the top-level
  menu)

Small changes inspired by Wednesday's discussions:

- Mac only: Gmsh now publishes its "file types"... That means that
  geo/msh/pos files now have nice icons, and that you can double-click
  on a geo/msh/pos file in the Finder to open it :-)

- removed support for fltk 1.0 (wasn't compiling anymore anyway)

- doubled the timout in GmshServer (2->4s): this seems to help on
  Windows (thanks to jkools@veeco.com)

- added warnings in the docs about the Attractor feature

- increased WB by 1 pixel in the GUI

- replaced more Msg(FATAL) with Msg(ERROR) where it makes sense

issue a small warning if we try to include or merge an unexisting file
in the parser

- store the points required by the transfinite algo in a list of vertices
  (instead of surf->ipar, vol->ipar)

- generalized Coherence for these lists of transfinite points

- added hacked version of the GNU matheval library to evaluate parsed
  functions efficiently ("a la getdp", but faster): I added a new
  directory (gmsh/MathEval) with that code, as well as a new configure
  option and a new define (HAVE_MATH_EVAL)

- generalized the plugin option code to accept arbitrary string options

- new plugin Plugin(Evaluate) that can evaluate arbitrary functions on
  scalar views (useful for example to create background meshes)

PS: Everything (octree + function evaluation) is now in place to write
a general plugin that can make any operation between arbitrary
views...

better test to check when to abort parsing

- Fixed second order mesh generation in 3D (on simplices only at the moment).

- In prevision of the extension to hexas, prisms and pyramids, all elements
are now derived from a new Element base class, which will be used in the
generalization of Edge/EdgesContainer in the future.

make parser && make depend

Abort parser after 20 lines with errors (instead of trying to parse
everything, even huge binary files :-)

- Simplified the bounding box computation. It is now computed as
follows (after each include/merge/open):

1. If there is a geometry (i.e., at least one geometrical point), the
bounding box is taken as the box enclosing all the geometrical points;

2. If there is no geometry but there is a mesh (i.e., at least one
mesh vertex), the bounding box is taken as the box enclosing all the
mesh vertices;

3. If there is no geometry and no mesh, but there are some
post-processing views, the bounding box is taken as the box enclosing
all the primitives of the last post-processing view.

This should fix the weird things that sometimes happen when we animate
scenes that do not contain any geometrical entities.

- Deprecated MergeWithBoundingBox()

- Removed Replot()

- Removed the "Last_NumberOfPoints" hack in the parser

- Removed CTX.expose

Fixed '//' with EOF before '\n' bug

small copy & paste bug (we tested Tree_Nbr(Points) twice instead of Tree_Nbr(Points)
and Tree_Nbr(Vertices))

And more airplane work!

- merged STL patch from Nicolas Tardieu. This patch permits to
  create an real elementary surface for each STL face. Until
  we have some code to directly remesh the STL data (which would
  be much nicer and cheaper), this is very useful. We can finally
  use STL representations to create meshable volume models.
  Thanks Nicolas !

- new option to color the mesh by physical entities (if an element
  belongs to multiple physicals, we use the first one)

- additional cleanup of the mesh drawing code

- big cleanup of the geometry creation section in the parser:

  * removed horrible Geo/DataBase.cpp
  * fixed all List-related memory leaks (a lot!)
  * added tests to check if we don't try to recreate existing
    entities (this should prevent many weird bugs due to incorrect
    input files)

- fixed LineLoop/EdgeLoop memory leaks

- many small fixes all over the place

Update copyright notice

Create temporary and error files in home directory to avoid file
permission issues (most notably on Mac OS X, when launching Gmush
from the Finder)

Added "append" argument to WriteView (so that "gmsh -convert file file"
can handle all the views in the input file and not only the first one).

New syntax bit: you can now use #aa[] to get the size of the list aa[]

Following a discussion with Laurent, we can now combine multiple views
(under certain conditions) into multi time step ones. This permits e.g.
to output separate .pos files for each time step, and still have a real
time evolution in gmsh. Pretty neat :-)

Removed extra arg in Init_Mesh

Removed extra arg for Init_Mesh

remove tMesh

new "Delete All;" command + only warn when reloading duplicate geometry
points.

Small changes for skeletton of new mesh format

- Slightly reorganized the visibility browser window (the "toggle"
  behaviour in the input field was confusing)

- added Show and Hide commands in the parser to enable scripting of
  the visibility stuff

- Moved Visibility.{cpp,h} into Common/ to avoid dependencies with the
  Graphics library in the parser

Fixed missing exception handling for PluginManager::action() (this led to
a crash when General.DefaultPlugins==0).

- new DecomposeInSimplex plugin
- new "Combine Views" command in the parser
- cleaned up View::tranform and View::smooth (+small bug fix for SLs)
- better check for transparency sorting
- make depend
- new View.AlphaChannel option to change the transparency
  globally for a given view (instead of having to change the colormap
  by hand every time)

With all the above, we can now generate very nice (and correct)
transparent iso-surfaces:

Merge "../tutorial/view3.pos";

minIso = 0;
maxIso = 2;
nbIso = 7;

Plugin(CutMap).iView = 0;

For i In {1:nbIso}
  Plugin(CutMap).A = (maxIso-minIso)/nbIso * i;
  Plugin(CutMap).Run;
EndFor

Delete View[0];
Combine Views;

For i In {1:nbIso}
  Delete View[0];
EndFor

Plugin(DecomposeInSimplex).iView = 0;
Plugin(DecomposeInSimplex).Run;

View[0].AlphaChannel = 0.6;

Cleaned up the whole Include/Merge/Open mess (removed the ugly
yyin/yyname tables in the parser, made the Merge routine reentrant
+ uniformized all the INFO/STATUS messages).

This should fix a nasty side effect from this morning's
commit (wrong yynames when doing multiple merges in the same
file).

Make Merge/Save/Print/Open behave like Include, i.e., open the file in the
same directory as the main project file (if the path is relative).