gr-qtgui: making (somewhat more) consistent case for function names.
gr-qtgui: adding function and slot to set a time display curve's color.
gr-qtgui: clean up
gr-qtgui: provide function and slot for setting the labels of a time curve.
gr-qtgui: Passing vectors of data to update plot for stability; also moving responsibility of keeping track of plot updates out to qtgui_sink instead of inside plot qidget.
gr-qtgui: moving towards allowing time plot to have multiple connections.
gr-qtgui: time domain sink now shows and receives updates.
gr-qtgui: adding time-domain only plotter.