Comment Connector doesn't update when arrow moves (#305)
Steps to reproduce:
1. Create a Data Flow Diagram
2. Create 2 Processes, joined with a Data Flow arrow
3. Create a Comment
4. Join the Comment to the Data Flow arrow, using a Comment Connector
5. Move one of the Processes
Result: The Comment Connector does not follow the arrow. It is stuck in its old position until the Comment is moved.