Added resampling to 8kHz so that it works with freeswitch (specify only L16/96/8000 codec in profile of media_engine/rtpfactory).  Changed logging to DEBUG level rather than INFO. Added channel_guard for stop response.
Added resampling to 8kHz so that it works with freeswitch (specify only L16/96/8000 codec in profile of media_engine/rtpfactory). 
Changed logging to DEBUG level rather than INFO.
Added channel_guard for stop response.

pgaval/unimrcp,AaronZhangL/unimrcp,pgaval/unimrcp,pgaval/unimrcp,MattRiddell/unimrcp,andrenatal/unimrcp,MattRiddell/unimrcp,AaronZhangL/unimrcp,AaronZhangL/unimrcp,andrenatal/unimrcp,MattRiddell/unimrcp,andrenatal/unimrcp