Extract the MTLModel protocol
Add spec for conforming models
Merge branch '2.0-development' into model-protocol

Conflicts:
	Mantle/MTLManagedObjectAdapter.m
	MantleTests/MTLTestModel.h
Improve documentation
WS
Change variable type
Remove unnecessary imports
Fix spelling
Add documentation to the MTLModel protocol
Remove -mergeValuesForKeysFromModel: from MTLModel protocol
Merge branch '2.0-development' into model-protocol
Move +modelWithDictionary:error: to the MTLModel protocol
Merge branch '2.0-development' into model-protocol

Conflicts:
	Mantle/MTLModel.h
	MantleTests/MTLTestModel.h
	MantleTests/MTLTestModel.m
Move MTLConformingModel initializer to class extension
Merge pull request #219 from MantleFramework/model-protocol

Extract the MTLModel protocol