Change how "connect/disconnects" are handled

This is not a bug, but a suggestion for improvement. Right now, if I pull the 
USB cable the Visual Programmer goes back to searching for Hummingbird. The 
problem with this is that if I'm working on a sequence, my sequence disappears, 
even if I just bumped it for a second and reconnected right away. It seems like 
it might be nicer if, in the event of a disconnect, we make everything grayed 
out (like "Play" or the sliders on the expression builder). Also put an image 
somewhere in the GUI showing that it is trying to connect.

Original issue reported on code.google.com by tlauw...@gmail.com on 18 Mar 2014 at 1:39

Merged into: #43

CMU-CREATE-Lab / create-lab-visual-programmer

Change how "connect/disconnects" are handled #176