Implemented a global language switch and translated titlepages

[didi1357]

Hi,

as previously suggested, this is my idea of a global language switch more or less copied from my private preamble.

This could probably ease the life of future users by not having to think about biblatex options and their order unless they have a specific bilingual use case. Most of them will just need to write their thesis or whatever in the one language approved by their supervisor.

Please also think about the used csquotes option:
german=guillemets

The package default would be quotes and I also think that quotes are much more popular in german. The last time I had german as a subject in school is already some time ago and even there we only used quotes. The last time I saw guillemets used in german was in some really old books.
Wikipedia, Anführungszeichen also seems to suggest quotes as primary default for german. Up to now I did not change that package option yet. I just changed the documentation and replaced the deprecated babel option with the now recommended autostyle.