Add automatic version number parameter also for the CSS resources, as we have for the JS resources.

What we already do in TVB is include the version number in the URLs for the JS resources as a parameter:
[JS_PATH]?[VERSION_NUMBER]
VERSION_NUMBER is now 1.1.2, and changing automatically with every new release.
VERSION_NUMBER is actually the same Genshi parameter that we use in TVB page-titles.

What we didn't feel until now as needed was to include that changing number also in the URLs for the CSS.
But we should do it with the next release.