Some encoder/decoder formats are currently not really working or
have not been thouroughly tested. To allow fearless hackers
fine tuning this flag is added to easily enable/disable these formats.
The sound and microphone redirection channels (and in part TSMF)
did not properly decouple encoding/decoding from the backends used
to play/record sound.
Encapsulating encoding/decoding in rewritten freerdp_dsp_* functions
with variable backends, simplifying alsa/oss/pulse/... audio backends.
