add SPICE_MSG_MAIN_AGENT_CONNECTED_TOKENS
add SPICE_MSG_MAIN_AGENT_CONNECTED_TOKENS

The msg is used for setting the number of allocated client tokens when
we notify the client that the agent is attached.

SPICE/spice-protocol,vdiot/spice-protocol,SPICE/spice-protocol,vdiot/spice-protocol,fgouget/spice-protocol,fgouget/spice-protocol,vdiot/spice-protocol,SPICE/spice-protocol,fgouget/spice-protocol