Implements `util.format` and `util.inspect`, formatted `console.log`

Caveats:
- adds some failing tests due to miscellaneous colony runtime issues (issues now cross-referenced, see https://github.com/natevw/tessel-runtime/commit/4608b513edf8f8221c4d40ed42ba1c230e05c9c1)
- `console.log` behavior not yet fixed (i.e. #176)
#305 should be fixed by https://github.com/tessel/runtime/pull/375, but this code might as well be left in. Should change "Lua" to type "Userdata".