Fixed #463, typo in urls.py
Merge pull request #764 from ostcar/issue-463

Fixed #463, typo in urls.py
Add last screenshots for German tutorial
Update translation source files
Merge pull request #776 from anjahitziger/Screenshots_3

Add last screenshots for German tutorial
Merge pull request #777 from normanjaeckel/TransifexSource

Update translation source files
Fixes #765. Avoids the django AbstracUser username validator

Also changed added a white-space in the default username again