optimizing 3D meshes without also optimizing 2D meshes with Lloyd

introduced mesh.optimizeLloyd to fix this

No commit message

2d meshing algo with -optimize does lloyd optim (tri or quad optim algo depending if recombine is selected)

No commit message

Propose to automatically create .geo file with a Merge command when
trying to append a scripting command to a non-geo file. Got the idea 
after the discussion with Robert Bou. (This is better than scripting
the Merge command IMHO.)

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

CreateTopologyFromMesh more accurate
Possibility to partition also Faces and not only GModels

never ever change the immutable vertex numbers: otherwise we cannot use
our algorithms from outside with prescribed boundary meshes

-> use MVertex::_index instead

(renamed setNum to forceNum to make sure we don't use setNum by mistake)

enhence statreport

fix warnings

oops, should not have committed openmp tests with jf

add benchmark/boolean

- 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

moment; we need to change the actual algorithm to ensure that we create
correctly oriented triangles in the first place)

moved all string options to std::string

*****************************************************************
WARNING: this has the potential to break things in subtle ways...
         PLEASE TEST AND REPORT ANY WEIRDNESSES
*****************************************************************

HAVE_XXX defines.

This fixes three longstanding problems:

- the API was hard to use because some headers had HAVE_XXX ifdefs, so
  that cient codes had to know how the lib was compiled to compile
  themselves

- we had to do make clean after each ./configure, which erased too
  much (e.g. most of contrib)

- make depend could include unwanted stuff since it redefined FLAGS

that the 2 steps are orthogonal
* added full-hexa subdivision algo

- fix bb computation to avoid model jumping around when adding points in z=0 plane
- pass interpol matrices as ref

There's no new functionality for now: PLEASE TEST THAT EVERYTHING
WORKS AS IT USED TO BEFORE.

reparametrization through harmonic maps enhanced