Apply the surface re-orientation hack to quadrangles (and to extruded
meshes!)

- mesh.algo -> algo2d and algo3d
- replaced most of the remaining radio buttons with Fl_Choices (requires
  less screen real estate)

- 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 experimental support for vertex arrays in the mesh drawing code
(only for triangles at the moment). This speeds up the drawing of large
meshes tremendously!

- removed support for mesh display lists

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

- 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

- add GUI for exporting characteristic length fields
- error->warning if lc <= 0
- don't enable POLYGON_OFFSET_FILL for 3D isos

Small corrections for ONFILE background meshes:

- should now work reliably interactively (and not only the first time
  the view is applied as a background mesh)

- fixed some memory leaks

- converted 2D_Recombine and SecondOrder to the EdgesContainer class
- removed the quadrangle hak and the ugly EdgesInVolume global from 3D_Coherence

- 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.

New raster ("bitmap") PS/EPS/PDF output

I forgot to commit these last week: it's just the beginning of some
cleanup of the old 2D algorithm (removed non-functional voronoi
insertion, fixed a couple of memory leaks, added some comments, etc.)

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

Removed extra arg for Init_Mesh

Added support to visualize mesh partitions. The partition info is currently
set as the physical entity number in the MSH file, but it would be trivial
to change it to something else (e.g., as soon as we generalize the MSH
format to take arbitrary number of tags per element).

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).

New native PDF support

Some morer work on second order elements

Added PNG support

Fix whitespace in copyright headers

Make headers self-contained

Updated copyright

Interface polish (buttons should not be resized when the size of the window is changed);
gl2ps update (not finished);