Demodulator will up-convert / down-convert by mixing VCO with incoming
IQ to shift frequency -- No longer limited to center freq. can listen
anywhere on the waterfall.
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.