make sure we are only only optimizing loops
connectivity bug image
alter the order of cutline connectivity derivation by using the COM of the vert loops
attempt to extend geometry first round of changes
initial support for connecting to existing selected geometry.  Be careful, this doesn't do any checks

to make sure the selection makes sense.
Final tweaks and commit for beta.

Branch Tag:  Contour Tools Beta
fixes #30
fixes #14
fixes #11
fixes #8

improves #33