Save device logs to rethinkdb.

lib/util/wireutil.js

@@ -55,6 +55,18 @@ module.exports = function(wire) {
   , envelope: function(type, message) {
       return new wire.Envelope(type, message.encode()).encodeNB()
     }
+  , makeDeviceLogMessage: function(serial, entry) {
+      var message = new wire.DeviceLogMessage(
+        serial
+      , entry.timestamp / 1000
+      , entry.priority
+      , entry.tag
+      , entry.pid
+      , entry.message
+      )
+
+      return wireutil.envelope(wire.MessageType.DEVICE_LOG, message)
+    }
   , makeGroupMessage: function(channel, timeout, requirements) {
       var message = new wire.GroupMessage(
         channel