Add Auto-Connect Feature

The introduction of auto-place has made modeling (especially when modeling from scratch) a lot faster. With a single click, you can append an element without having to worry about the position of the element. With a little bit of logic, connections could be created automatically, too. When the user hovers the connect entry of the context pad, a possible connection could be previewed, which can then be created on click.

Implementation Notes

• context pad supports hover callbacks (both mouseover and mouseout)
• auto-connect feature finds suitable candidate for connecting
  • if candidate is found it is connected on click
  • if not candidate found connect tool is activated on click
• allow hooking into finding suitable candidate through event bus (e.g. prevent suggesting connection between participants)