Skip UserModel saving when there are no changes in either local or linked children.
Skip UserModel saving when there are no changes in either local or linked children.

Improves performance on bulk operations.

nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus