Upgrade to remq 0.0.3, remove serialization, add auto pub/sub, tests

Lots of changes:

1) Upgrade to remq 0.0.3 which has a new API and better performance
2) Remove built-it JSON serialization in favor of raw string messages
3) Automatic polling to pub/sub switch-over, much simpler interface
4) Added some basic tests
5) Added a benchmark

Note: Because of the new remq data structures, upgrading will require
clearing any existing remq:* keys. Until the API is stable, this
will probably happen a few times.