revert some changes from jf's last commit

make depend + fix warnings

Arghhhhhh! Fixed very nasty out-of-bounds bug in 2D mesh algo...

It led to seemingly random Windows slowdowns/crashes: we were passing
random numbers to curve interpolation, and straight line interpol does
"while(not in bounds) i--" which would take forever to get/ back into
reasonnable interval

fix depend

new boundary layer mesh generator

refactored smooth value/smooth normal code into single SmoothData.* file

remove extra volume

add more step/stl benchmarks

general, but ProjectPointOnSurface for example would fail on plane
surfaces)

added General.MinX, General.MaxX, etc. so that we can easily get the
min/max of a model (useful e.g. to create a box around an imported
STEP model)

added example of mixed step/geo model

rewrote the interactive edge/face link finding routines in terms of GModel

(hence we can now create volumes from OCC faces in the GUI)

add tooltip for mesh quality (dave)

use the 3D Delaunay by default (if tetgen is available)

fix opti crash with Delaunay algo (forgot to classify new vertices in correct region!)

include the geometrical entities defined in this script (since we
import THEM into GModel *after* we've parsed the file)

orientation bug in extrusion

- make it easier to build universal binaries on Mac
- remove unused arg in transform functions (an prepare the terrain for periodic meshes)

better text in warning dialog when appending string to non-.geo file

polish

- print num vert+elm after each generation
- reork tutorial a bit

displays nowadays often have more than 1024 pixels

cleaned last gcc warnings

tagging gmsh_2_0_0

small things

- added warning dialog before attempting to append a scripting
command to a non-geometry file

- fixed mean plane computation for periodic curves

- added headers + ramn indent on Attractor files