Fix bug #34611: bevel overlap limit
The previous fix limited overlap, but is sometimes
too conservative, and artists want way to turn off
the limiting, so added 'Allow Overlap' option to
modifier.


git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@56259 954f8c5b-7b00-dc11-b283-0030488c597c