Removed old class docs that were no longer needed in this release.
Fixed an issue that was causing calls to cloudservers to needlessly re-authenticate.

Issue: https://github.com/rackspace/pyrax/issues/4
Added the 'halfClosed' parameter to the load balancer create() call.
Added support for keychain storage of passwords.
Merge branch 'master' into working
Added some novaclient exceptions to the pyrax.exceptions namespace to make it easier to handle them in applications that use pyrax.
Updated setup.py to reflect that pyrax is no longer beta (should have been done with 1.2.0). Removed unneeded import.