[FEATURE] allow for audio direct processing

We do an audio capture to temp and then process that to get the desired audio quality.

Some users have expressed the possibility of processing all the audio stream in a pipe, I have done that but if the SBC/PC has another task running this could ruin your capture, I have done that.

But I will expose it as a optional feature in the users.conf file, by default with a temp file, at code level it's something like this

timeout $5 rtl_fm -p "${RTL_PPM}" -f "${FREQ}M" -s "${rxbw}" \
            -g 44.5 -E deemp -F 9 - | \
            sox -t raw -r "${rxbw}" -e signed -b 16 -c 1 - ${WSATP}.wav rate 11025

stdevPavelmc / FAASGS

[FEATURE] allow for audio direct processing #24