lots of improvements to boundary layer generation: we can now constuct
and mesh models with entities connected to boundary layer points, edges
and faces

fix position of BoundaryLayerPoints

- removed static GMODEL (can now have multiple models)
- added infrastructure for new post-processor module

fix some of the demos + clarify some comments

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!

depend

changes for new projection surface interface

fix typo in msg

add big warning for Delaunay algo

prepare for post-pro changes by moving all post-pro stuff in separate directory

enable new Delaunay for plane surfaces

experimental: don't use it for now

fix fouriermodel depend

- 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>

_L,_H -> _LL,_HH

cleanup

1D transfinite mesh algo was completely broken.

sigh.

increase size of bbox for 2d algo (cf example)

- fix include for box version
- don't optmize BDS.cpp for now: it crashes with gcc 4.1 (e.g. on debian etch)

- only save mesh vertices that are used by elements

- fix warnings + indent + memory leaks in new Field classes

- temporary fix to avoid crashes in new field manager when post-pro
  views are reloaded or removed at run-time

Jonathan