Changes

transceiver: make control command parsing arguments const

Change-Id: I2f3aa5363c337791451a388f394d7351d3183908

transceiver: replace sprintf() with snprintf() in ctrl_sock_handle_rx

Change-Id: I7b725534c83a759e7b8f72f605dbcc38d778b1f2

build: add --disable-multi-arfcn configure option

- add configure flag to disable Multi ARFCN support
- compile Channelizer, Synthesis, RadioInterfaceMulti and fft.c only when enabled
- guard Multi ARFCN-specific code with ENABLE_MULTI_ARFCN
- avoid requiring fftw3f when Multi ARFCN support is disabled

Change-Id: I2495c5b5c79f2fe74bef83902058e1d2207c1f3c

radio: improve API documentation in RadioDevice

Change-Id: I7b41c549d743ad180a1ddcd8c0313e1003860070