Implemented multiple GUI trace figures w/ docking

figures are docked to a unique group, 'tracePlotsGUI', using
setFigDockGroup (added to helper functions). Figures are docked to main
window at first, but pressing 'undock' for this group will break out the
4 figures and restore the group to its previously used size, position,
and layout. This is persistent across sessions, so should only be need
to be set once!