fix 144: enable to select initial questionnaires for responsible contributors
translation updates
minor translation fix
minor refactoring
complete translation
Merge pull request #445 from janno42/default_questionnaires

Default questionnaires for responsibles
fix some python3 compilation errors
some backwards-compatible 2to3 changes
remove last traces of the profile picture
fix and refactor the comment review form

before, the text fields were empty initially, and the form was bypassing the mechanisms of ModelForm.
moved to xlwt-future dependency
py3: tell travis we're using python 3.4 now. remove pypy, it doesn't support python 3.
make vagrant setup py3 ready
changes by 2to3
remove a encoding related hack that's not necessary with python3
rename all __unicode__ methods to __str__
use python3 super calls