Made the x axis ticks and name constant--what appears there does not depend on what pv is selected.
Changed x axis units to seconds.
Commented out old/unused actions from the list view context menu.
Removed dependence of plotted pv values on a 'valuesDisplayed' setpoint. Now, the user can specify a time threshold in seconds and all measurements made within that threshold window will be plotted.
Time controls are now fully implemented. Also, tried mixing around the look of the control panel. The goal was to make it better: don't laugh. :)