Draw draggable control points
Disable start and end control points
Default to 3 control points
Add channel connection pins to router
Add more customisation options to dragBehaviour
Connection colour matches conversation colour
Points are only visible when line is selected
Fix bug with connection colouring
Change the way selected components enable line control points
Drawing bounding box as first element in selection
Styling adjustments
Fix test cases
Add extra test for utils
Add more tests for control points and drag behaviour
Merge pull request #4 from praekelt/feature/issue-4-control-points

Let user create draggable control points