Support values animation mode with just a single value, should be equal to a set animation per SMIL.
Breaks most of Dr. Hoffmanns reference animations in his SMIL+SVG testsuite, that are all made of values animations. (see http://hoffmann.bplaced.net/svgtest/index.php?s=en&in=start).
Created attachment 139200 [details]
Committed r115429: <http://trac.webkit.org/changeset/115429>