fix(XmppConnection): use status instead of the connected field

The connected flag is flipped to true as soon as transport connection is
established by Strophe(such as WebSocket TCP), but it doesn't mean that
the connection is ready to send stanzas yet.

modules/xmpp/XmppConnection.js

      * @returns {boolean}
      */
     get connected() {
-        return this._stropheConn.connected === true;
+        return this._status === Strophe.Status.CONNECTED;
     }
 
     /**
         return this._stropheConn.service;
     }
 
+    /**
+     * Returns the current connection status.
+     *
+     * @returns {Strophe.Status}
+     */
+    get status() {
+        return this._status;
+    }
+
     /**
      * FIXME.
      *
     }
 
     /**
-     * FIXME.
+     * Wraps Strophe.Connection.connect method in order to intercept the connection status updates.
+     * See {@link Strophe.Connection.connect} for the params description.
      *
      * @returns {void}
      */
-    connect(...args) {
-        this._stropheConn.connect(...args);
+    connect(jid, pass, callback, ...args) {
+        const connectCb = (status, condition) => {
+            this._status = status;
+            callback(status, condition);
+        };
+
+        this._stropheConn.connect(jid, pass, connectCb, ...args);
     }
 
     /**