Replaced custom utility function with sequence equal
Added failing test for attaching a NEW object graph root
Added support for attaching a NEW object graph root
Cleaned up UpdateConfigurationVisitor
Cleaned up tests a bit
Cleaned up DbContextExtensions
 - Merged PR

   - Added new test for new aggregate (more to come)

 - Fix for adding associated entity right before calling UpdateGraph.
 -Test class refactoring, getting ready for more comprehensive testing.