add remoteDebugUrl into database so that it is accessible from api

lib/db/api.js

@@ -151,6 +151,8 @@ dbapi.saveDeviceInitialState = function(serial, device) {
   , statusChangedAt: r.now()
   , ready: false
   , reverseForwards: []
+  , remoteConnect: false
+  , remoteDebugUrl: null
   }
   return db.run(r.table('devices').get(serial).update(data))
     .then(function(stats) {
@@ -163,6 +165,20 @@ dbapi.saveDeviceInitialState = function(serial, device) {
     })
 }
 
+dbapi.setDeviceConnectUrl = function(serial, url) {
+  return db.run(r.table('devices').get(serial).update({
+    remoteDebugUrl: url
+  , remoteConnect: true
+  }))
+}
+
+dbapi.unsetDeviceConnectUrl = function(serial, url) {
+  return db.run(r.table('devices').get(serial).update({
+    remoteDebugUrl: null
+  , remoteConnect: false
+  }))
+}
+
 dbapi.saveDeviceStatus = function(serial, status) {
   return db.run(r.table('devices').get(serial).update({
     status: status