Remove Failure category from passing test cases

Some of the test cases marked as Failure have started passing. Need to
ensure that these testcases are run on a regular basis.
Wrong category was removed

Intended to remove Failure category instead of UnitTests category.
Merge pull request #2422 from Conceptual-Design/TestCatagorization

Remove Failure category from 22 passing test cases
Folded "DynamoViewModel.Exit" into "updateManager_ShutdownRequested"
marked bad list test as failure
Fix to handle longest lacing on empty arrays

It used to crash, it now doesn't execute the function

http://adsk-oss.myjetbrains.com/youtrack/issue/MAGN-4566
RecordedTest/CodeBlockNodeTest do not need to "shutdown the host"
Removed unwanted argument from "DynamoModel.ShutDown" method
Updated signature of "ShutdownRequestedEventHandler" delegate
Merge pull request #2436 from Benglin/MinorCleanUp

Clean-up of DynamoModel.ShutDown methods
Merge pull request #2435 from DynamoDS/LongestLacingFix

Fix to handle longest lacing on empty arrays
Increase reference count for array elements
Merge pull request #2440 from ke-yu/fix_memory_corruption

Increase reference count for array elements
Merge branch 'master' of https://github.com/DynamoDS/Dynamo into Revit2015
Merge pull request #2443 from Benglin/Revit2015

Merge branch 'master' into 'Revit2015'