Default selection state changes.
When nothing is selected, the UI acts as if the 'all activity' widget is selected. All Activity is no longer selectable, but is implicitly selected at all times. When other selections are made, its color is faded in the treemap.
The overlaps and all activity colors are now in a 'legend' area at the bottom of the sidebar, instead of looking like recordings.
Moved the 'start a recording' button back towards the top of the sidebar, and removed the 'recording' look it had.
The 'latest X' recording is now at the top, separate from the 'all activity'.
Pulled the colorpicker tooltip javascript out into its own file, from the RecordingWidget script.