Rackspace CLBs

Addresses #289. Milestones are:

- [x] LBs
- [x] error pages
- [x] LB stats
- [x] nodes
- [x] VIPs
- [ ] domains
- [ ] usage reports
- [x] access lists
- [x] monitors
- [x] session persistence
- [x] connection logging
- [x] throttling
- [ ] caching
- [x] protocols
- [x] algorithms
- [x] SSL termination
- [ ] metadata

(Not sure if all of these resources will make it into this PR)
Will this always have the same time format? If so, we may want to parse the string to a `time.Time` object for the user.