adds initial commit of entity cloning
More work on deep cloning, have test passing for IContent
More test written for deep cloning.
More code and tests written for deep cloning.
More code and tests written for deep cloning.
More code and tests written for deep cloning.
Simplifies much of the deep cloning with the DeepCloneHelper and adds tests
publicizes DeepCloneHelper
Fixes cache providers to ensure it stores and resolves clones
Merge branch '6.2.0' into 6.2-cachefixing
Fixes up some cloning with value types and collections
Merge remote-tracking branch 'origin/6.2.0' into 6.2-cachefixing