Shouldn't need separate WBFM/FM/NFM setting this way -- Just "FM" and
then set arbitrary bandwidth by dragging.
Also removed redundant demod resampling stages left over from early
experiments.
Had to make my own portaudio and rtl-sdr binaries. The available
packages weren't compatible somehow. Also wxWidgets wxPack doesn't
include OpenGL support but it's easy enough to compile.