- work on plugin user-friendliness (short help & co)

in a force field (should be generalized e.g. for Lorentz force,
but that a TODO ;-)

Some code cleanup & added comments.

- invert #define logic (HAVE_MESH, HAVE_POST, HAVE_SOLVER, ... instead of HAVE_NO_MESH,
  HAVE_NO_POST, HAVE_NO_SOLVER)

- simpler plugin script save

- more work on slepc integration

simulated annealing.

finished up first pass at remote view management:

* interactive stuff is now almost feature-complete (including
  multi-step, axes and adaptive refinement)

* plugins can now be executed on remote views

* renamed GmshRemote->ConnectionManager & GmshDaemon->GmshRemote

renamed most gmsh* classes

Plugin/Triangulate.cpp
Post/PView.cpp
Post/PViewDataRemote.h : Change for compilation on SunOS

CMakeLists.txt : Change mkl libraries on windows

change Spline to BSpline in GSHHS plugin (I hoped MinStraitsFactor Option would allow to use Spline but it's not the case...)

new Tetrahedralize plugin

stuff, like plugin drawing

Encapsulate toolkit-dependent global drawing functions in new
drawContextGlobal class, and add a static drawContextGlobal to
drawContext, with a default version that does nothing.

This allows to have a completely virtualized drawing system: we can
now ship a library with a fully working graphic system, indepedent of
the widget toolkit. A client code just needs to subclass
drawContextGlobal to get working graphics (see
e.g. api_demos/mainAntTweakBar.cpp)

extractVolume could miss some full (sub)elements for non-simplices

Improved reduction algorithm when generators of highest dimension are
present.
Added Betti number computation using coreduction to the UI.
Added support to quadrangles (not yet to prisms, hexaherdons or pyramids
due to unresolved issues).
Bugfixes.

re-committing work from last two days after server crash:

- refactored old Geo code (new/delete)
- moved DrawPlugin to Plugin
- move from matheval to mathex
- move from Flu_Tree_Browser to Fl_Tree
- fixed crash in Triangulate plugin

- moved GUI to FlGui + added experimental QGui to test Qt

- fixed most MSVC and gcc compiler warnings

- converted some remaining tabs to whitespace (that's why the patch is
  so large; please try to remember to indent with 2 spaces and not
  tabs when you commit stuff to CVS)

- merged modified patch from Konstantinos Poulios to allow saving
  physical/partition as element tags in mesh formats that don't
  support them natively