cleanup for archives generation
refactoring: rename jquery.phpfreechat.*.js to pfc-*.js because too much dot makes problems on few servers
refactoring: rename jquery.phpfreechat.*.[less|css] to pfc-*.[less|css] because it does not work on few servers
refactoring: less and css filenames (next)
prepare 2.1.1
make release: if version does not exist as a tag, get the latest commit id as the version number for the git checkout