Themes::get_all() used to work only on the first call.
Themes::get_all() used to work only on the first call.

Once self::$all_themes was set, it would try to work with $themes, which was not set prior.

Now all it does is if it exists, return it, kthxbye.

git-svn-id: d0e296eae3c99886147898d36662a67893ae90b2@850 653ae4dd-d31e-0410-96ef-6bf7bf53c507

dragonmantank/Habari,dragonmantank/Habari,dragonmantank/Habari