Merge branch 'maint'
wxgui: Fixes to solve issues using GL sinks on OS Xplotter/plotter_base.py: Create explicit OpenGL context, check if window is shown before realising context & only create PaintDC is paint triggered by WM message (OS paint event)Added SetSizeHints to WX sink windows so sizing occurs correctly
wxgui: fix scaling issue of nongl FFT plot (issue #523).
wxgui: add some noise to the fftsink_nongl test case.
wxgui: make dummy set_callback stub in nongl sinks.
Doesn't work, but also doesn't break the code.
Added PaintDC to 'plotter_base' so WX GL sinks will work under Windows.Changed 'notebook' SetSelection (deprecated) to ChangeSelection.
wxgui: implement persistence without using glAccum
wxgui: dead code removal and formatting cleanup
wxgui: allows LEFT click to set a flow-graph variable to the adjusted X value on either the FFT or waterfall display.
Also available in: