Unasync Rackspace First Gen Cloud Servers

This PR unasyncs the Rackspace First Gen Cloud Servers API `cloudservers` as described in [JCLOUDS-40](
https://issues.apache.org/jira/browse/JCLOUDS-40) and [JCLOUDS-49](https://issues.apache.org/jira/browse/JCLOUDS-49).

All unit tests pass. Live tests are pending due to the removal of legacy endpoint from the service catalog. Once my access has been reenabled, I will run the live tests and update this PR.

DO NOT MERGE!