test args-backward
full unit coverage for parseargs
full unit coverage for shellescape, timid_relpath
unit coverage for req_is_abs
unit coverage for wait_for_all_subprocesses
unit-test for unprintable(). last unit-test todo.
Merge branch 'master' into unit-coverage

Conflicts:
	tests/functional/simple_test.py
don't run coverage for pypy;
py26 doesn't have a consistent exit code
Merge pull request #26 from Yelp/unit-coverage

Unit coverage