Removed the HET_Selector and HET_SelectionBuffer. Internal workings were
too dependent on the Processing PGraphics3D "recorder" implementation
and proved too unstable across versions. Functionality was moved to
WB_SelectRender3D and no longer relies on the recorder mechanism.
Added methods to HE_Face, HE_Edge and HE_Vertex to get center and vertex
offset along normal.
Added a few hemesh examples on selection and color