removed global THEM

(once more step towards nicer integration of old GEO stuff)

moving to new post-processing database

                    *** WARNING ***

do not upgrade if you need plugins or adaptive views: these have not
been ported (yet) to the new database

                    *** WARNING ***

- removed static GMODEL (can now have multiple models)
- added infrastructure for new post-processor module

enable new Delaunay for plane surfaces

experimental: don't use it for now

- changed '-convert' syntax to process multiple files at once

- added lateral entities in list returned by extrusion commands

- preliminary work to interface more parser functions with general
  GEntities

- we can now export simple GModels as.geo files (points, straight line
  segments, plane surfaces, ruled surfaces and volumes are treated
  correctly; all non-straight-line curves are exported as splines; all
  non-plane/ruled surfaces are not exported)

- tentative fix for the unv export problem reported on the mailing
  list (fprintf() buggy on some machines??)

- new IO (both read and write) for structured grids using the NASA
  Plot3D format (for Olivier)

- temporary fix for creation of second order vertices on periodic
  curves and periodic surfaces

- speedup 2nd order vertex creation

- never create MFaceVertices if we don't know the parametric
  coordinates (this will screw up the 2nd order algo!): create
  MVertices instead

- fixed u,v coords of vertices after elliptic smoother in
  meshGFaceTransfinite

- added "-format msh1" and "-format msh2" shortcuts to quickly
  select the version of the msh format from the command line +
  added "med" and "cgns" formats

- moved gui guidelines in separate file

better configure for MED

- added exception to GPL for triangle/tetgen
- fixed some command line switches
- added option to antialiasing OpenGL rendering

- new option Geometry.Tolerance (or -tol on the command line) to set the
tolerance for the old CAD engine, for OCC healing and for STL import

- removed more unused options

better names for mesh algo #defines

OpenProblem -> OpenProject
MergeProblem -> MergeFile

more on clcurv options

new option to compute char lengths from curvature + removed most unused mesh options

remove aniso + old extrude from interface

more occ work

spec fltk theme with -theme + minor tweaks

- finished Nastran BDF implementation (read+write in all BDF formats:
  free field, small field & long field)
- improved UNV and Medit import
- added detection of bad vertex indices in all import routines
- fixed bug in 2nd order quad constructor

Implemented new binary MSH file format (both read and write).

A 250Mb mesh file (6 million tetrahedra) is now read or written to disk in
less than 10 seconds (on my powerbook's slow hard drive).

minimize the number of files that include GmshVersion.h: it's annoying to
recompiletoo many files just because the version string changes

moved most OS-dependent functions in OS.cpp