- removed context.default_plugin

- changed the main so that we load the plugins *before* we set the
  options (this way you can save your favourite plugin options in
  .gmsh-options, too)

force flex buffer flush after an error

fix make parser on linux

don't include matheval in commercial releases

prefix all the xmath functions with "x_" : some of these are defined
in the new C++ math lib with the same names

avoid error when trying to apply a plugin to a view that has been deleted

get rid of asprintf

matheval.c -> matheval.cpp

small tweaks

save the colormap if it's different, too

don't allocate too many value inputs for the plugin windows

missed those files in my previous commit

- only save the options that differ from the default values (unless we
  explicitly ask to save everything)

- tweak the auto doc routines

- 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...

left some CVS dirs in the source archives

upgrade gl2ps to 1.2.0

use abort() instead of exit() when we really want to exit *now*

INFO->DEBUG for sys2x2 and sys3x3_with_tol

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

typo

some more bgmesh cleanups

3d background mesh example

re-enabled ONFILE background meshes in the 3D case

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

added a couple of nice examples

1.52

Only enable POLYGON_OFFSET_FILL for volume faces if we draw the
edges. Otherwise it looks pretty bad since we draw connected faces
with large differences in orientation.

reverting to old rpm build method

build source rpm, too

add volume test for 2nd order tets in UNV format, too

- enable lights by default
- remove obsolete comments about MergeWithBoundingBox

Fixed orientation of polygons produced by CutTriangle2D so that we can
use a TWO_SIDE light model everywhere. This also fixes the ugly "checkboard
patterns" when using custom scales on continuous maps.