[bp/r48193][bp/r48195][ENH] CodeMirror upgraded to latest stable version (3.16) & [ENH] Flv and Mp3 packages are added to the composer.

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@48257 b456876b-0849-0410-b77d-98878d47e9d5