Blender Git Loki

* Cleanup of subsurf unwrap code

Now take subsurf levels and type from the modifier stack (Now simple
subdivision will work too). Subsurf unwrap won't work if there's no
subsurf first or after mirror in the modifier stack. This is done to
alleviate having to set subsurf levels in two places, usually user will
want the tool to autodetect the setting from the stack. This sets the
paradigm that will be followed by mirrored unwrap as well.