modified patch from philip kelleners (mostly for irix)

- fixed .msh save of negative volume 2nd order hexas

fix info msg

need to add new vertices into Surface->Vertices (for possible later extrusions)

link with GmshPlugin before GmshCommon (for dave)

add option to renumber the nodes in .msh files (to avoid gaps in the sequence)

pretty print

better fix for discrete curves: we don't make any assumptions on the
node numbering anymore (and just regenerate the connectivity)

small fixes so we can mix discrete curves with regular curves and mesh
mixed surfaces

fix interactive mesh drawing + initial_only aniso

make "initial mesh only" option visible in scripts

draw interactive Delaunay in correct coordinate system

- fix discrete surf (for the 100000th time)
- new Status N command in parser to force mesh status
- create reverse discrete curves

workaround for Read_Mesh limitation when reading discrete closed
curves (missing last vertex due to List_Insert...)

fix crash + cleanup jf's msg

set char length from lines (useful if we want to mesh 2D from boundary repres)

cannot init iterator with 0: breaks on gcc 4.1

minimize the number of files that include GmshVersion.h: it's annoying to
recompiletoo many files just because the version string changes

new plugin to extract the geometry edges

moved most OS-dependent functions in OS.cpp

characteristic lenghts, that would lead to HUGE meshes (this is one
of the most common causes for erroneous bug reports on the mailing list)

ask confirmation to overwrite a mesh file when clicking on "Save Mesh"

remove obsolete BGM structure

removing dead code

better export mesh as post-pro view

polish

removed the STEP parser: it's unusable, it makes the parser bigger,
and it introduces conflicts in the syntax.

- better fallback when outside the octree
- disable bgm when optimizing in netgen

Rewrote the background mesh code to use the new post-pro octree instead
of the old brick stuff. It's 100x faster ;-)