Fix part of #34640: colors darkening when using the vertex paint blur tool.

The problem was that vertex colors only have 8 bits of precision, and integer
division always rounds down, so after some color blending iterations everything
gets darker. Instead use integer division that behaves like round() instead of
floor() for blending operations.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@56293 954f8c5b-7b00-dc11-b283-0030488c597c
Fix #35077: cycles incorrectly rendered an empty with dupligroup that was
dupliverted by its parent.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@56294 954f8c5b-7b00-dc11-b283-0030488c597c