fixed full-quadrangle recombine algo:

- run globally, not for each surface
- assign entities to elements
- split line meshes
- correctly re-tag vertices as 1st order
- plug memory leaks

cosmetic

add little menu to choose the quality measure in Options->Mesh->Visibility

fixed small bug when drawing the boundary of a prism for a time step > 1

replaced ExportLCField with ExportMeshStatistics (lc + gamma, eta, rho + elem num)

fix "color mesh by partition"

make the previous commit only apply to macs

use the Apple's recommended way of detecting big endian machines, WITHOUT
using autoconf

add note to remember how to use compiled vertex arrays

removed unused stuff + handle SURF_DISCRETE in MeshDiscreteSurface

ArrowLocation->GlyphLocation

add num of physical groups in stat window

Fixed performance problem(s) for very large meshes with a huge number of
physical entities:

1) use a temp tree for physical entities in read_mesh

2) we should not set partition=physical for the old mesh format

3) only do getFirstPhysical in draw_mesh if we need to (and warn if
   we do and if there are many many physicals)

optimize 2d iso plots with vertex arrays

polih previous commit

2 big optimizations for meshes that contain a lot of line elements:

- speed up Read_Mesh (by introducing temp tree in curves)
- use vertex arrays for lines in mesh drawing code

update to latest gl2ps

fix warning

make the extrusion stuff work with SimplexBase too

fix warning

make the code compile on Mac OS X 10.4 (gcc 4.0.0)

- removed the "Dirty" flags in the CAD data structures

- when reading the mesh from an entity that has no CAD, create a "discrete"
  CAD entity

- remove the drawing of discrete entities that don't have a BDS
  representation during the geometry drawing

make it compile on my mac

removed remaining Discrete Line/Surface stuff

add entries about Visibility, Clipping and Transparency

two more fl_ask -> fl_choice