Mass "protokoll" notifications

This is a new section inside the admin panel. This feature allows you to send mass messages (those displayed in ```protokoll.php```). It uses custom messages to avoid "support-team" bad usage. Once you select the message to be sent and confirm the action, the script will choose only the members that have been active during the last 7 days to recive the notification.
If the notification is sent successfully a ```addInfoBox``` alert will confirm it.
A new icon and category have been added to protokoll.

![administration](https://cloud.githubusercontent.com/assets/6611118/3379927/3f9542b2-fbfa-11e3-82da-1b1fd4e18c28.png) This icon must be uploaded to ```images/protokoll/``` with the same name as the new category (in this case ```Administration.png```).

Well that was the formal explanation. Do you think it will be usefull for things, like for example, showing an alert when patch notes are updated or stuff like that?

![patch notes](https://cloud.githubusercontent.com/assets/6611118/3379940/767c5022-fbfa-11e3-9d85-11fdef0d24eb.png)