new boundary layer mesh generator

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

enhancement of gmsh Surfaces

JFR

fixed interpolation of ruled surfaces created by extrusion

fixed interpolation of trimmed ruled surfaces

are more correct)

fix interactive modification of mesh attributes

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

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

bidir db: phase 1

start opencascade integration

- SVG export
- more work on new geo database