Fix function redefinition

1. Fix the routine that detects the removed functions and pass them to
the changeset applier
2. Added testcases for modifying the arguments of a function
Fix function redefinition - function name check

1. Include functionname in equality check
2. Added function rename testcases
Refactor function
Renamed "AsyncTask.ExecuteCore" to "HandleTaskExecutionCore"
Renamed "NodeModel.RequestVisualUpdate" to "RequestVisualUpdateAsync"
Introduced an empty "NodeModel.RequestValueUpdateAsync" method
Merge branch 'master' of https://github.com/DynamoDS/Dynamo into defectfix
Enable mark and sweep garbage collection strategy
Disable Heap.Verify() in mark and sweep
Beginning of zero touch example.
Clean up SyncDataManager
Create new guid and send NodeDeleted event
Add comment
Allow empty nodemodel set
More properties, methods, and comments.
Add regression test case
Add newly added test case to failure category
Add defect link to test case
Merged few files for earlier review
fix to changes in autocomplete insertion