Using super() for base class function calls

After bob.bio.base#64 (closed) is merged, we can go ahead and use super() to call base class functionality here, too. This mainly should affect constructor calls.

mentioned in issue bob.bio.base#64 (closed)

created branch 20-using-super-for-base-class-function-calls

changed milestone to %May 2017 Hackathon

added Easy label