Initial version of transactions. Shell command implemented as an example. Still needs channel cleanup on app side, handling a device dying in the middle of a transaction, and getting device list back to normal.

lib/wire/index.js

@@ -8,6 +8,9 @@ wire.ReverseMessageType = Object.keys(wire.MessageType)
   .reduce(
     function(acc, type) {
       var code = wire.MessageType[type]
+      if (!wire[type]) {
+        throw new Error('wire.MessageType has unknown value "' + type + '"')
+      }
       wire[type].$code = wire[type].prototype.$code = code
       acc[code] = type
       return acc