Update German translation

[Ragnar-F]

I've fixed and adjusted several texts to make it consistent with the official German translation of RimWorld. All changes have been tested and are working.

Some notes:

• Added periods to some option descriptions for consistency with older descriptions (might be worth adding these to the English texts as well)
• Changed T-V distinction ("Sie" → "Du") for consistency with official translation
• Changed pawns' right-click menu options to imperative mood (verb + subject) for consistency with official translation
• Replaced some "erzw." with "erzwungen" to avoid overuse (generally only necessary to save space)

[pardeike]

Gut gemacht!