todo tetgen: recategorize vertices+tets in each separate region

missing headers

small fixes for mesh opti

reimplemented mesh optimization -- seems to work nicely with netgen (grids
generated with tetgen seem to be wrong)

reduce POINT memory footprint (remove all unused stuff!)

cleanup

more cleanups

cleanup

bidir db: phase 3 -- move all the old geo stuff into Geo/

bidi db: phase 2 -- continued

bidir db: phase 2 -- removed all (well, most of) the old data structures and
algorithms

bidir db: phase 1

temp fix for stephen: call old mesh algo when we don't have MEdgeLoops (i.e. for gmshFaces)

Enhancement of the OCC interface

Plane surfaces are now recognized and the
usual gmsh "cross" is drawn correctly

occ work

:i

start opencascade integration

more mesh edit work

new GModel::writeGEO (only implemented for gmshModel for now; goal is to be able
to implement this for other derived model types (like OCC) later, too)

force orientation of mesh to match the orientation of the geometry

fix missing SIGN in NR