fix for dummies in watch
fixed file watcher to handle empty directory name
added tests for custom ast nodes
updated element trace test to test for amt change
Convert to using xml file for test input.
Resolved a merge conflict moving changes in trace testing to their new fixture.

Merge branch 'master' of github.com:ikeough/Dynamo

Conflicts:
	src/DynamoRevitTests/DynamoRevitTests.cs