#6 SSDPRequest should include client MAC

[Greg Combs]

The SSDPRequest in RioServerList.cc should include
the MAC address of the client machine, in order to
properly register it's intentions with the rio server
software. It's format is as follows:

"upnp:uuid:1D274DB0-F053-11d3-BF72-
0050DA689B2F\nMAC:GOES:HERE\n"

Greg