remove elliptic - same as Transfinite with Mesh.Smoothing > 1

- finished volume extrusion
- cleanup ExtrudeParam (plug memory leak + remove unused stuff)
- make netgen the default 3D algo for now (since it actually works)

make explicit regions in extrusions DEPRECATED

remove more attractor crap

remove aniso + old extrude from interface

fine tuning

fix off-by-one bug in the computation of u

forgot to add this

extrude edge+face (only "recombined" for now; we'll implement subdivision
into simplices "globally" later)

start work on extrusion

don't build metis and ann by default anymore

some initial steps before reimplemeting extrusion

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