Modular Custom CSS: inline documentation updates.

git-svn-id: https://plugins.svn.wordpress.org/modular-custom-css/trunk@1052115 b8457f37-d9ea-0310-8a92-e5e31aec5664
Modular Custom CSS: mark 4.1-compatibility.

git-svn-id: https://plugins.svn.wordpress.org/modular-custom-css/trunk@1052116 b8457f37-d9ea-0310-8a92-e5e31aec5664