quick generalization of Plugin(Extract): we can now extract arbitrary
combinations of the field's components

- 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)

- 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...

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

1.52

pretty print

- cleaned up the octree code (renamed some files, added copyright
  notices, indented everything)

- backported JF's doc from the texinfo file into the c++ code (the
  documentation is actually generated automatically by Gmsh with
  "gmsh -doc"!)

- replaced nPoints with nPointsU and nPointsV in CutGrid

- fixed a couple of printfs + removed some unused variables

- added new General.GraphicsFont option

- added GUI stuff for font selection, quadric subdivisions, selected
  lines

- improved Graph2D's handling of fonts

- removed Print.EpsFont and Print.EpsFontSize options

doc -convert

"gmsh -convert file file" now also translates meshes into the newest
format (in addition to parsed->binary post-processing views)

modify alt+shift+l to match the old behaviour

document second order simplices

fixed (?) log scale for continuous maps (and maps where we don't check
for IntervalsType: scalar points, etc.)

Refined mesh drawing code:

- draw surface element edges and/or faces
- draw volume element edges and/or faces
- consistent color choices between surface and volume elements
- wider geometry lines
- better defaults

- 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.

lena->lenna

wording

removed obsolete (and wrong) description of the physical entity
numbering requirements.

- 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

use full url in "back" links

merged small patch from prudhomm@mit.edu

pretty print

Added automatic documentation generation for plugins