Moving towards zero config and supporting more UDP commands

Hi @pauly

Here's another collection of commits for you based on further investigation of the WiFi Link UDP commands and further understanding of UDP Sockets

1. Eliminated the need to specify the IP address for the host in the config file by broadcasting the UDP command across the local network (46eb16b). If the config file contains the host IP, that will be used. If it is missing, the UDP command will be broadcast. This is a further step toward zero-config!

2. I've added support for a two additional UDP commands:
    * Setting the timezone on the WiFi Link from the server running the Gem (d231add). This is a fairly nominal functional addition, but helps make sure timers and sequences happen when expected!
    * Turning off all devices in a room (252209c). This is a pretty crude implementation which you may wish to refactor. However, it helps this end for now!!!!

Hope they work for you and can make it into the next generation of the Gem (and therefore the Siri Proxy plugin)