* [mod_opus] add cfg setting to overwrite the fmtp stereo param coming from remote. Eg: incoming SDP has stereo=1 but we want a mono call so we answer with stereo=0.
sprop-stereo will be set to 0 too.
* [core] opus: use switch_core_max_audio_channels() with remote fmtp stereo=1 to allow disabling of stereo.
Port video buffer to also support audio and remove original STFU jitter buffer
Add some more resilience to video packet loss
Add codec control mechanism for both call-specific debug and codec/call specfic params
Make opus function better in packet loss and latent situations
Use new codec control prams to make JB lookahead FEC optionally enabled or disabled mid-call
Add Param to allow JB lookahead to be enabled.