MGCP_Emulation: Move from connetion-based to endpoint-based model

In the end, we will often see two connections that relate to one
endpoint, so let's dispatch based on the endpoint name and not based
on the connection identifier.

In the BSC case, we have
* two MGCP connections on one EP in case of RTP/IP based Abis
* one MGCP connectio on one EP in case of E1/T1 based Abis

In the MSC case, we have
* two MGCP connections on one EP: BSS and MSS/MNCC side

Change-Id: I8cd7395ee7b076a9a9ef513cc1b71f2db5009845
1 file changed