Merge pull request #562 from ke-yu/ChocoButter

Undo/redo; copy/paste for DS function node
Minimal DS integration test
Missing file
Merge branch 'ChocoButter' of https://github.com/ikeough/Dynamo into ChocoButter
Build config fixes
Null document handle fix
refactored IdlePromise into RevitServices

also removed redundant delegate constructor calls across solution
Dummy commit to trigger rebuild
refactored DynamoUpdater into RevitServices
Build system fix to use macro symbols for RevitUIAPI
Merge branch 'ChocoButter' of https://github.com/ikeough/Dynamo into ChocoButter
Minimal Demo of DS in Revit execution