Allow a pool/factory of MRCPv2 connection agents to be defined with the MRCPv2 profiles. Agents are specified using a comma-separated list as follows:

      <mrcpv2-uac>MRCPv2-Agent-1,MRCPv2-Agent-2</mrcpv2-uac>

and are selected for a new session using a simple round-robin scheduling.

The following definition is still legitimate and is equivalent to the pool/factory of one MRCPv2 connection agent.

      <mrcpv2-uac>MRCPv2-Agent-1</mrcpv2-uac>

Nothing has to be changed.