Resolve PEP8 issue W291

* W291 trailing whitespace
Resolve PEP8 issue E231

* E231 missing whitespace after ':'
Resolve PEP8 issue E231

* E231 missing whitespace after ':'
Merge branch 'w291' of https://github.com/berendt/osc

Conflicts:
	osc/build.py

Resolved merge conflict.
Merge branch 'e231' of https://github.com/berendt/osc

Conflicts:
	osc/build.py
support groups in maintainership requests
fix project checkout

linked packages may contain project.diff or override files so it does
make sense to check them out. We honor -e/-u for that reason.