fix [#34603] ALT-F fails, freezes, CPU=100%

The way beauty fill was working was too fragile and prone to eternal loops,
Solution used is to is to store previous states and ensure edges don't get rotated back into those.

Also added an optimization to avoid testing the same edge rotation many times - using edge tags to only re-test edge rotations around areas that have been modified.


git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@55579 954f8c5b-7b00-dc11-b283-0030488c597c