Added a visualizer that shows a timeline of how agents are using their
separate modules/brains. To see it, hover over a particular robot with
the mouse and press the 'U' key. This brings up a colored timeline
whose width is always from the start time to the current time. Each different color
corresponds to a different mode/brain, and will match of color of the robot
itself when using that particular mode/brain. As different modes/brains are
chosen, they appear on the far right (current time) and gradually get squished
to the left. Stretching out this window horizontally can provide better resolution.

Also added vshost files to the ignore list for Git.