I18n: Remove broken / unsupported translations.

See http://users.xfce.org/~nick/broken-i18n/ for files and logs.

Use https://www.transifex.com/projects/p/xfce/ to upload fixed versions or request a translation team.
I18n: Update translation bg (100%).

111 translated messages.

Transifex (https://www.transifex.com/projects/p/xfce/).
Remove unneeded files.
I18n: Add new translation ru (100%).

111 translated messages.

Transifex (https://www.transifex.com/projects/p/xfce/).
I18n: Update translation ug (99%).

110 translated messages, 1 untranslated message.

Transifex (https://www.transifex.com/projects/p/xfce/).
I18n: Update translation ug (100%).

111 translated messages.

Transifex (https://www.transifex.com/projects/p/xfce/).
I18n: Update translation en_GB (100%).

111 translated messages.

Transifex (https://www.transifex.com/projects/p/xfce/).
I18n: Add new translation en_AU (100%).

111 translated messages.

Transifex (https://www.transifex.com/projects/p/xfce/).