revert changes

make code compile on Mac again

better label for "constrain bg mesh"

fix support for multiple light sources (+ add a couple of options to set
the light color and specular reflection exponent)

typo

Don't call Mesh_Quality() in GetStatistics()

added vertex arrays in volumes to store the boundary of the cuts
when we draw them "as surfaces" (for Philou, not tested yet)

fixed small bug in ReplaceDuplicateCurves where we woudn't eliminate
identical CIRC/CIRC_INV ELLI/ELLI_INV pairs

re-add return statements in functions returning non-void. JF: my compiler
wants this (and he's right)

small copy/paste mistake in my last commit

make depend

- fixed a couple of gcc warnings + added missing o->end() in
  jf's StructuralSolver plugin

- fixed the view option code: FLTK > 1.1.5rc1 breaks our use of
  widget->changed()...

- added background mesh support in the aniso algorithm

- fixed a couple of corner cases in the computation of 2D/3D isos
  (+renamed the routines)
- fixed small box size bug in the GUI

airplane work: reorganized the option panels in the GUI (more descriptive
labels, same categories for geo/mesh/post, etc.)

draw the clipping/cut plane dynamically when we change the coefficients

added an option to cut only volume elements

draw intersection of cutting planes with the bounding box

- added an option to draw the bounding boxes

- simplified the color_scheme options

- added tooltips to make the discovery of shortcuts easier

- added Orientation() members for hexas, prisms and pyramids

- use det3x3() instead of ad-hoc code everywhere it makes sense

little hack to visualize overlapping multi-patch spheres with constant
offsets (use timeStep<0...)

add "post-processor" keyword

add "reset" button in clipping window

clip plane doc update

simple clip example

generalized + added GUI for clipping planes

make depend

mesh smooth normals

remove debug message

- moved the smooth normals stuff into a separate file
- added smooth normal support for surface meshes (very nice!)

removed the bool hacks

note to self

bgm fix

add an area constraint on the elements in the initial mesh to make
the refinement nicer