Fix #390

The issue here was configSchema is an attribute within attributes and so revertAttributes and attributes get the same instance of it when clone is used. Later calls to _.equals fail when only configSchema has changed.
Optimizations of markToRevert: Switch to using $.extend instead of _.cloneDeep and only when type is not a "ThangType"
Merge pull request #650 from dpen2000/Issue390

Fix #390