At handoff redesign

This pull request totally updates the visual design of handoffs. They now use circuiting. Colors are randomized on all of your old teams, new teams now take advantage of a "color" option in the interactions JSON object. So when you create a handoff, its color is generated just like the members and remains that color when you refresh (on your old teams it will just keep randomizing). 

Things to check:
-Old team handoffs display alright
-New team handoffs display right, stay the same when you refresh and reload

Known issue: Right now you can't edit the color of the handoffs. It took more effort than was worth it to copy the color box from the members to the handoffs if we are going to throw that out anyways. 

Request: When testing this, using actual/realistic teams would be very helpful. As of right now, circuits could end up on top of or behind events if you layer them on purpose. I am not sure if this is going to come up enough in actual teams to be worth solving. Let me know!!