PR: CloudMonitoring functionality

I've been working on introducing Cloud Monitoring functionality for the past week or so. It closely follows the Rackspace ReST API, as set out here: http://docs.rackspace.com/cm/api/v1.0/cm-devguide/content/overview.html

There are around 15 resources associated with Cloud Monitoring - all of which have their own operations. I've tried to follow closely what we already have - but made things a bit more modular. Each resource is fully unit-tested and has a JSON file for each expected GET/POST response.

Another core change is that I've moved all the files from ```AbstractClass``` and ```Base``` into ```Common``` for consistency. I've changed all the namespaces accordingly - make senses to keep global files in one directory rather than two

The next step is to document the new CM feature, but I haven't had time yet. Will do either tonight or some time this week with code examples :)