Fix for missing calls of BaseMath_ReadCallback() when accessing vector/color elements.
This bug was causing wrong color blending results in Freestyle color modifiers.
Problem report from Light BWK through personal communications, thanks!

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk@61070 954f8c5b-7b00-dc11-b283-0030488c597c
Minor code improvements: avoid unnecessary Python object allocations in Freestyle color blending.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk@61071 954f8c5b-7b00-dc11-b283-0030488c597c