Further fixes to make things work in Chrome again

fixes all the stuff that was broken in chrome stable, still works in FF. Please test:

* [x] basic loading of the designer page
* [x] adding a component shows the comp, the two arrow buttons to the left and right of it, and the listen/broadcast channels
* [x] clicking the listener/broadcast arrow button pops up a selector menu
* [x] clicking to pop up another selector menu closes an already opened one
* [x] picking a new color for a listener/broadcast changes the channel visualisation