compile tetgen by default so we get feedback on machine-specific problems

try different ordering when swapping fails

fix display of normals for very "thin" surfaces with curved boundaries:
this new algorithm should be better

All modifications are commentarized because
this feature is not functionnal : the transfer from
Gmsh to Tetgen is OK, but the transfer from Tetgen to
Gmsh is not : all the mesh (points, lines,
surfaces, volumes) must be recreated in Gmsh...

New fonction to use Tetgen 's algorithm
Attention : several problems
  - the method deinitialized of Tetgen is not seen by the compiler
  - it seems that the data structure tetgenio is destroyed after its creation,
so that all meshing procedure is dine in the constructor

Adding Tetgen version 1.3

New plugin to compute the modulus and the phase of a complex-valued field
in-place, in one simple step. One could already do this with Plugin(Evaluate),
but it was a little bit cumbersome.

don't draw the trajectory if LineWidth==0

if a curve is "discrete" but has no BDS representation, don't draw anything
in the geometry routine: we draw the elements in the mesh routine.

don't store lines in vol->Simp_Surf : it screws up the saving of Physical
Lines! Use vol->Lin_Surf

simpler handling of env vars

fixed crash when using Plugin(CutParametric) in a script ("v->" -> "v1->")

fixed crash when using Plugin(Evaluate) in a script ("v->" -> "v1->")

fix small bug with overflowing feedback buffer and PDF output

print compiler info

remove unused test

don't force CC on sgi anymore

extra \

sgi fixes

sgi compile fix

simpler options for sgi

use same rules as for our own parser to  avoid any implicit rules on
.l and .y files (fixes compile pb on irix with sgi's old 'make')

update gl2ps

force ./unix2dos (if . is not in the path)

reset the list of trsf pnts if we redefine a transfinite entity multiple
times by mistake