Allow end user to tweak foreign phrase lists

Migrated from: https://tracker.clearos.com/view.php?id=1567

Reported by: Peter Baldwin

The "phrase lists" for DansGuardian are provided in different languages. By default, all languages are applied when a particular phrase list is enabled. For example "badwords" phrase list will enable all the bad words in:

• Dutch
• French
• German
• Portuguese
• Spanish

This can be problematic when a bad word in one language is a normal word in another. For this reason, an end user should be able to specify which languages should be active with the phrase list engine.