pothos-widgets: added range controls to freq domain plots
pothos-gui: connected value changed signals for spinboxes
pothos-widgets: use DoubleSpinBox for range controls
pothos-gui: remove mouse handers -- properly accepted in widget
pothos-widgets: added zoomer and mouse press accept
pothos-widgets: allows for dragging from QGroupBox title
pothos-widgets: move mouse event accept into common class
pothos-gui: move double click properties open to GraphObject
pothos-gui: graph object emits context menu, graph widget can ignore
pothos-gui: replace mouse handler with contextMenuEvent
pothos-gui: reimplement move detection, cleans up scene filter
pothos-widgets: zoomer needs to reinitialize the axes
pothos-widgets: combine zoomer and picker, add to wave plotter
Merge branch 'plot_work'