Refactor some common test code

Cherry-picked from 9be96c963cc92b8edc008fc9c4c5090373f6be8d on
fixoptions.py3k branch

Conflicts:
	supervisor/tests/test_options.py
Coverage: can't find default config file behavior
Coverage: find default config file
Coverage: pass file= to print_function, test Options.help

Cherry-picked 8cee926b31a59edee08842d0705299f6273c053f from
fixoptions.py3k branch

Conflicts:
	supervisor/compat.py
	supervisor/options.py
Merge pull request #420 from msabramo/increase_coverage

Increase coverage