CloudSearch2 updates

Changes the following:
* Generated layer1.py from service model
* Layer1 -> CloudSearchConnection
* Layer1 now uses JSON instead of XML responses
* Updated layer2 objects to use JSON and generated layer1
* Updated doc service to remove attributes which are no longer valid
* Updated search service to remove attributes which are no longer valid and
  modify existing attributes which have changed
* Updated unit tests and integration tests for all of the above
Documentation Updates

* Fix class/module names in the docs files for cloudsearch and cloudsearch2
* Remove param doc comments that no longer exist
* Normalize the parameter help text for domain_name