Allow injection of custom consitency default and consistency mapping
Test that the default consistency and consistency mapping are propagated from the scaling group collection to the scaling group
Configure the default consistency and consistency in makeService
Merge branch 'master' into as-263-paramterizable-consistency

Conflicts:
	otter/models/cass.py
Change get_consistency_level to a consistency object that is initialized based on the special case mapping and a default
Use consistency object everywhere in the models
Change the makeService call to create a Consistency object
Fix linting issues
Fix unitgration test too
Change consistency back to a callable
Change cass models to take a callable everywhere, and change modify state test to test that everything is read and written to as quorum
Modify the API to pass a callable to the models based on the configuration, modify tests to test just the consistency configuration
Update config.json
Just use the CassScalingGroupCollection, as suggested by lvh
Merge pull request #634 from rackerlabs/as-263-paramterizable-consistency

As 263 paramterizable consistency