meshPartitionOptions::partitionByExtrusion assigns all extruded elements to the same partition as the source element

- 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

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

- merge OCC64 patch from Jose Paulo Moitinho de Almeida

* implemented first rough draft of VTK mesh writer

  did in high
* added mesh generation error log summary
* removed Parallel subdir (this is now handled by the message class)
* removed Box subdir and consolidated batch processing in a single
  routine
* made List_T into a class
* reduced dependencies in Pview*.h so we can eventually add the post-pro
  interface to the public API

untabify

api cleanup: use ByTag consistently (emphasises slowness of lookup)

- clean up GModel API (xxByTag -> getXx, numXx -> getNumXxes, ...)

start reducing header pollution (removed Gmsh.h + cleaned up GModel & co)

cleanup previous commit + move "carve hole" routines in separate file

Temporary fix for 'could not find extruded vertex' bug.

This is a serious bug, which is related to the way we use std::set to
search for points: cf. benchmark/bug/test_problem_point_set_search.cpp

THIS PROBLEM IS ALSO PRESENT IN BDS. WE NEED TO FIND A BETTER FIX!

- prepare group of nodes in UNV (for Guillaume)
- prepare delaunay for connected volumes
- test 2nd patch from Michel for phase1() extrusion

bof

- polished mesh option strings in gui
- merged modified extrusion patch from <mi.benham@free.fr>

- tentative fix for the "mysterious" crashes on Windows:

  I think that the problem comes from the new recursive tetra
  classification, where we probably overflow the stack on Windows. The
  fix is to request a larger initial stack size through the linker.

- added option to control label saving in unrolled geo files

- only test for neg jacobians for 2D/plane meshes for now

- fixed several compiler warnings

- 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)

- boundary layer can now be generated by using a post-pro view for the
  normal field

- added more operations on lists in parser (FExpr * FExpr_Multi, etc.)

- new "hole carving" code to create extruded grids carved out around
  some surfaces (the resulting cavity can be filled with "grout" using
  the unstructured algos)

- check if bboxes of post-pro views are not == VAL_INF before adding
  them to the model bbox (bug report from Renaud Sizaire)

- fixed crash in LCM_xxx tensor drawing code when no tensor points are
  available. (This piece of code should be cleaned up further--no time
  for that now.)

- generalize Levelset plugins so that they work on point data sets

- fixed missing return value in OCCVertex::reparamOnFace

- added code to highlight orphan entities (dave's idea)

- added gui for incomplete second order elements

- removed ugly static variables in 1d algo

- made sure we remove all 2d order vertices before generating new ones

- reimplemented subdivision of extruded meshes
- fix indent + unused var + gcc warnings all over the place

print warning for now when extrusion mesh is not recombined

better tol in extrude

- finished volume extrusion
- cleanup ExtrudeParam (plug memory leak + remove unused stuff)
- make netgen the default 3D algo for now (since it actually works)