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.
No longer passing anything through the main thread which was causing
audio and IQ interrupts on UI events -- hopefully improves OSX jitter.
SDRThread can now have unlimited Demodulator bindings.. :)
