Frequencies should be incremented (internally) by 16000 when in wbfm mode

[wizardishungry]

On hold!

rtl_fm increments wb_fm frequencies by 16000.

We should increment our CV controlled frequency by the same so that the displayed tuning frequency matches our day-to-day perception of what the center of FM tuning looks like.

[wizardishungry]

I tried this with CBS FM in new york and I'm not sure it (subjective opinion) helps reception without turning on stereo fm support (see #2). See wikipedia's description of fm signal.