bmesh operators: use operator type-flag to specify which operations require normal-calculations and which operations require selection flushing.
eg, no need to flush selection after 'Smooth' tool, no need to recalculate normals after 'Select Similar'.


git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@56035 954f8c5b-7b00-dc11-b283-0030488c597c