added stagemonitor widget

Stagemonitor widget is a little stagemonitor icon, which is injected in the monitored webpage (if activated).
It offers to view the stacktrace of the request and notifications if thresholds are met. Configurable thresholds are the number of SQL queries, generic error notification and request-response-time.
The widget shall support the developer through instant feedback about not optimal parts on the developed page.

![1](https://cloud.githubusercontent.com/assets/4292951/3980716/83f9cd82-2865-11e4-96ec-3dc5a5016387.PNG)
![2](https://cloud.githubusercontent.com/assets/4292951/3980753/0ece1864-2866-11e4-8f1b-fbf245e2c3f4.PNG)
![3](https://cloud.githubusercontent.com/assets/4292951/3980719/8c3b8062-2865-11e4-9850-94177fb22f70.PNG)