Add Select More (ctrl np+) and Select Less (ctrl np-) to UV editor

These tools allow to extend or shrink uv selection like in edit mode, but also take selection mode, sync mode and sticky mode into account.


git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@56194 954f8c5b-7b00-dc11-b283-0030488c597c