Fix changeSetCompute on deleting code in a CBN with a function definition

1. Fix delta compute when code was deleted in a CBN but the function
definition did not change.
2. Testcases
Merge branch 'master' of https://github.com/DynamoDS/Dynamo into GlobalFuncTable_Initialize
Merge pull request #1589 from junmendoza/GlobalFuncTable_Initialize

Fix changeSetCompute on deleting code in a CBN