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)
One solution would be to write out the full name for the directory, and then shorten it on the import:
``` go
import acl "github.com/rackspace/gophercloud/loadbalancer/v1/accesscontrollist"
```