run-tests.js previously relied on shell wildcard expansion, and did not specify
full paths. This uses common.expand to handle globbing internally, and specifies
the full path, so jshint can find all the files.
Plenty of errors surfaced with better test coverage. Aside from fixing
the broken implementations, this also prompted me to fully implement
the dirs command.
Also changed the run-tests script to always set cwd to the test folder,
so that tests that change cwd don't affect others (ehum, that'd be
mine.)
More tests to follow.