Ringbuffer are lockfree data structures...

Flush all will be used when registering a new RTP stream and thus set
new resampling to make sure we do not resample data with wrong sampling
rate info

test for multiple conference participants

MainBuffer::getData
MainBuffer::putData
MainBuffer::discard
MainBuffer::flush

Now, creation and deletion of rngbuffers is automated.

It fixes the problem concerning discarding the data

However, Microphone Capture using alsa cannot be copied inot ring buffer.
The application was by passing the micRingBuffer in this case...

This buffer is not one coresponding to the call ID since we do not
want to send back the incoming data
In case of a conference, we just need to extend this id to a set of ids
and mix them together if the set is greater than one

The audio frame is copied into the right ring buffer given the CallID
as an argument

Remove unused mute function

Add notification incoming call.

Change setup directory name to ".sflphone".
Fix volume control.