revision r56196 adding uv select more/less used 4 nested 'for' loops, 
rewrite to use only 2.

also use generic, reusable functions for selection flushing so each operator doesn't need to implement its own.
and merge more-less operation into the same function, just call the selection flush function with select/deselect arg.


git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@56197 954f8c5b-7b00-dc11-b283-0030488c597c