Description of problem:
When you resize a swimlane in the attached BP, the connecting lines are moved, leading to a lot of layout work being undone.

Version-Release number of selected component (if applicable):
/bpmsuite-6.1.0.GA

How reproducible:
Happens in Chrome / Firefox / IE11

Steps to Reproduce:
1. Open attached BP
2. Resize the orange swimlane at the bottom
3. Notice that lots of lines which were carefully laid out have moved

Additional info:
See attached video and BP for testing.