Fix #35681: cycles excluded layers still got evaluated before and after
rendering even if they were not used on any render layers.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@57352 954f8c5b-7b00-dc11-b283-0030488c597c
Fix #35658: OpenEXR (from Maya) - missing passes

Added some special case for two-component channels name.

Maybe magic could be simplified to just use last char of
channel name as an id, but extra paranoid check never hurts.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@57353 954f8c5b-7b00-dc11-b283-0030488c597c