bulletproof FindCurve/Surface + uniformize error messages

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

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

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

make parser && make depend

- 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

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

remove tMesh

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

- 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).

Forgot these

Big Levelset rewrite (+ cleanup of all other plugins).

Not finished yet, but I need to commit this now so that I can use it
with the boss tomorrow at work.

This version should compile and have all the old features working,
plus some extras (levelsets of scalar/vector/tensor 1D, 2D and
3D simplectic views).

JF: 'Plugin(XX).Save' is now deprecated. Use 'Save View[XX] "filename"'
instead.

Fix 2 gcc warnings

- Fix pb with index returned by Extrude Surface
- Upgrade gl2ps

remove warnings for now

Fix + generalize index retrival for geometrical transformation

- Comment JF's last changes in the parser until we fix the syntax

- Update gl2ps

- Small fix in the configure script to better detect fltk-config

- Fix Parser/Makefile (for older versions of bison)

Add 'newl' (synonym for 'newc') and fix the docs

Speed up variable creation/retrieval by replacing 'List_T *Symbols_L'
by 'Tree_T *Symbols_T'.