initial commit with waterfall widget code and demo
support old playback files
trace controls thin line version
better trace button alignment
fix for crosshairs demo
Merge branch 'waterfall' into ui-improvements
unify options in controller, add view menu (unconnected)
stop updating iq when view option unchecked
update plot visibility on menu and state change
move automatic worker thread starting to WaterfallPlotWidget subclass
make examples' #! line consistent
factor rendering iteration out of thread method
Now able to reset a waterfall model, as well as change the model a waterfall uses.
WaterfallModel no longer requires x data to start with.
Merge remote-tracking branch 'rwarren/waterfall' into ui-improvements

Conflicts:
	pyrf/gui/waterfall_widget.py
first attempt at waterfall integration
fix waterfall in speca-gui
return numpy arrays from sweep device
reduce waterfall history, with sweep these could get large
waterfall plot: use logging module