Fix #34034: keyframe display of color/curve buttons was broken after revision
53132 which changed the RNA index to -1 for these. Also made it so that these
buttons no longer display "Insert Single Keyframe" and only "Insert Keyframe"
as you can't edit individual components here so it's only confusing.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@54237 954f8c5b-7b00-dc11-b283-0030488c597c