Updated Lithuanian translation
thetvdb: Include The TVDB source

https://bugzilla.gnome.org/show_bug.cgi?id=672933
thetvdb: Include tests

https://bugzilla.gnome.org/show_bug.cgi?id=672933
Updated POTFILES.in
Updated Polish translation
Updated Slovenian translation
Updated Czech translation
Updated Brazilian Portuguese translation
travis: Update to Ubuntu Trusty

We require quite new dependencies that are not easy to back-port to
Ubuntu Precise, the default version that Travis CI uses.