German translation

I've finished the German translation talking to the informal "Du" (similar to being on a first-name basis with the user). There might be still some minor mistakes in there, but for now, this should be a nice start for people wanting a German version of django-wiki.

There are some minor changes in your code in order to remove some spelling mistakes and inconsistencies.

I also changed the gitignore file not to ignore *.mo, since those are needed and, the user probably doesn't want to compile them everytime he installs django-wiki