fixed ugly extrusion syntax (finally!)

extrusions are now specified in the same way as all other transformations
(the old syntax is still available, but is deprecated)

rewrote the smooth normal routines:

- the averaging is now done by clusters, which is much better for
  geometries that have sharp edges  (it's a little slower, but the
  visual results are much better)
- there is now only a single smooth normal container in the mesh
  (instead of one per surface)

- new button under the graphic window to temporarily disable mouse
  selection (speeds-up redrawing of very large models + permits to
  rotate/zoom-in a model in selection mode even when the whole screen
  is full of selectable entities--e.g. a surface mesh)

- new "lasso" selection mode (to select entities using the same kind
  of lasso as the lasso zoom: just Ctrl+click, then drag the mouse in
  selection mode; the shortcuts are the same as for the lasso zoom)

- it is now possible to unselect entities using the middle mouse button
  (only for the creation of physicals at the moment; not sure if it's
  useful in the other cases)

- new button in visibility browser to invert the current selection
  (very useful e.g. when multiple physical entities are associated
  with a given elementary entity, in order to "peel" away the model
  when adding new physicals; cf. philou)

- changed meaning of Escape shortcut (cancel lasso or toggle mouse
  selection) + restore standard fltk Escape handling for all dialog
  windows

- updated copyright string

- new mesh label mode (coordinates); all label types are now also
  available for mesh vertices

- added option in 'Print Option' dialog to disable printing of help
  strings

- added a comment string with the date when creating a new file

- new snapping grid for adding points in the GUI

- new button under the graphic window to temporarily disable mouse
  selection (speeds-up redrawing of very large models + permits to
  rotate/zoom-in a model in selection mode even when the whole screen
  is full of selectable entities--e.g. a surface mesh)

- new "lasso" selection mode (to select entities using the same kind
  of lasso as the lasso zoom: just Ctrl+click, then drag the mouse in
  selection mode; the shortcuts are the same as for the lasso zoom)

- it is now possible to unselect entities using the middle mouse button
  (only for the creation of physicals at the moment; not sure if it's
  useful in the other cases)

- new button in visibility browser to invert the current selection
  (very useful e.g. when multiple physical entities are associated
  with a given elementary entity, in order to "peel" away the model
  when adding new physicals; cf. philou)

- changed meaning of Escape shortcut (cancel lasso or toggle mouse
  selection) + restore standard fltk Escape handling for all dialog
  windows

- updated copyright string

- new mesh label mode (coordinates); all label types are now also
  available for mesh vertices

- added option in 'Print Option' dialog to disable printing of help
  strings

- added a comment string with the date when creating a new file

- new snapping grid for adding points in the GUI

Removed all compile-time depdencies on byte ordering (big- or little-
endianness). Replaced them with run-time conversions where necessary (only
for packing/unpacking of colors into unsigned ints). Performance hit
should be negligeable, but this will allow to compile Universal Binaries
on Mac in a single step (instead of having to compile the PPC/big-endian
and the i386/little-endian separately, which wouls be a royal pain in the
butt).

make depend

trying to fix the transfinite volume bug introduced by the 'left' and
'alternate' transfinite surface changes made a while ago

make "BoundingBox{x,X,y,Y,z,Z}" actually do what the documentation claims
it does

Don't reinitialize the symbol tree in OpenFile.

(We don't reinitialize the option database, so why should we reinitialize
the variables? Using a single global symbol tree we can again define
variables with -string "" on the command line.)

cleanup STL remesher GUI

moving all external code to contrib subdirectory

use it now with -partition N for N partitions
only works with tets and triangles
output should be added (useless for now)

explain #list[]

generalized the solver interface to allow permanent listening on a
socket for whoever wants to connect (gmsh -listen)

the polling should also be less CPU hungry in this new version

next step is to add new commands to the protocol so that solvers can
directly transmit data to merge (geometry, mesh, etc.) in addition to
messages and filenames

fix memory leak + missing depend

reset the list of trsf pnts if we redefine a transfinite entity multiple
times by mistake

Removed the last bits of the "Discrete Surface/Line" stuff.

Gmsh can now simply read a .msh file, and use it as the boundary mesh
of a 3D mesh. For an example on how to do this, cf.
demos/sphere-discrete.geo.

This complements nicely the STL remeshing stuff: Gmsh can now
for example very easily be used to extrude surface meshes that
come from other tools.

removed unused stuff + handle SURF_DISCRETE in MeshDiscreteSurface

make the code compile on Mac OS X 10.4 (gcc 4.0.0)

- removed the "Dirty" flags in the CAD data structures

- when reading the mesh from an entity that has no CAD, create a "discrete"
  CAD entity

- remove the drawing of discrete entities that don't have a BDS
  representation during the geometry drawing

added all the missing "Combine" modes in the parser

The FLTK folks have deprecated fl_ask(), so we need to replace the calls
to fl_ask() with calls to fl_choice()

- Generalized the "View" parser so that we can add new elements more easily
  (the code is *much* shorter, but unfortunately about 10-15% slower)

- Upgraded all post-pro file formats to handle curved (second order)
  elements: SL2, VL2, TL2, ST2, VT2, ... The new version number for the
  postpro files is 1.4

- Added code to automatically split the curved elements into linear
  elements when the view is created. WARNING: this is only a temporary
  solution: weshould generalize Adaptive_Post_View to handle these curved
  elements.

- better test for drawing geo+mesh bbox
- ask if we want to uncompress gz files during merge

- fixed double free in case there is an error in tSprintf

- new StrRelative command

- small demo on how one can add a generic title to a plot using
  Plugin(Annotate)

change the behavior of "-string string" command line option to match the
bahavior of "-option file"

- New "Discrete Line" commands (similar to the Discrete Surface commands, but for
  curves).

  This permits e.g. to use Gmsh's extrusion mesh generators on 2D meshes (with
  boundaries) imported from other programs, and have all the useful elements
  generated (both volume and surface).

- Don't use Ctrl+m for File->Merge, as it is a reserved keyword for
  Window->Minimize on OS X:
  * File->Merge is now Shift+Ctrl+o (since it's in some way a variation of
    File->Open's Ctrl+o)
  * Tools->Options is now Shift+Ctrl+n

- added new "spectral" colormap (truncated hsv)
- added GUI button for elliptic mesh + geometry coherence
- added GMSH_MAJOR_VERSION, GMSH_MINOR_VERSION and GMSH_PATCH_VERSION
  in the parser

allow negative line loop number in surface definitions

- fixed the "unix socket name is one character short" problem on
MacOS and AIX. Unfortunately, this required the client code to be
slightly modified as well (and as a consequence, old versions of getdp
will for example not work with new versions of Gmsh on MacOs and
AIX). But it's better to do things "the right way" (TM) for people who
want to connect using different languages (Perl, Python).

- moved the GmshServer stuff in its own class

- added missing rules in parser makefile (so that the parser gets
  rebuilt automatically when one changes Gmsh.y or Gmsh.l)