Add the DEBUG and ANALYSER control parameters

Add the option to control if DEBUG information is sent to the serial
line; add the option to control if the spectrum ANALYSER is enabled on
the firmware. The control of these parameters allows size savings up to
~39%.

TX Original: 9.458 bytes
TX with DEBUG: 8.368 bytes
TX with ANALYSER: 7.018 bytes
TX without DEBUG and ANAYLSER: 5.808 bytes
Total saving is ~39% with both options disabled

RX Original: 10.446 bytes
RX with DEBUG: 9.378 bytes
RX with ANALYSER: 9.938 bytes
RX without DEBUG AND ANALYSER: 7.270 bytes
Total saving is ~30% with both options disabled