update zh_CN translation
thetvdb: callback from resolve always return media

https://bugzilla.gnome.org/show_bug.cgi?id=733287
thetvdb: call the callback with episode cache miss

If the cache is up-to-date and we hit a cache miss, call the callback.

https://bugzilla.gnome.org/show_bug.cgi?id=733287
doap category core
doap: add <programming-language>
lastfm-albumart: Add tests