Don't change the opacity of Genericons using custom colors or inherited link colors. The user can customize these colors anyway, so it doesn't make sense to fade them further, which also messes with the transitions. Retain the opacity change when Genericons are sing the natural icon colors.

git-svn-id: https://plugins.svn.wordpress.org/quickshare/trunk@776712 b8457f37-d9ea-0310-8a92-e5e31aec5664