Calling client.end() when detaching the element

This implements #14

Author: sandro-k

mqtt-connection.html

@@ -262,6 +262,8 @@
 
       },
 
+      _createdConnection: false,
+
       observers: [
         '_usernameOrPasswordChanged(username, options.username, password, options.password, withCredentials, auto)',
         '_autoChanged(auto, withCredentials)'
@@ -280,6 +282,12 @@
         }
       },
 
+      detached: function () {
+        if (this._createdConnection && this.client){
+          this.disconnect();
+        }
+      },
+
       _usernameChanged: function (username, old) {
         this.set("options.username", username);
       },
@@ -443,10 +451,13 @@
         if (this.options.clientId && this.options.clientId.length == 0){
           this.set("options.clientId", this._generateClientId());
         }
+
         this.options["queue"] = this.packetQueue;
 
         this.client = mqtt.connect(this.url, this.options);
         this.client.setMaxListeners(this.maxListeners);
+
+        this._createdConnection = true;
       },
 
       /**