Added Base/Notify module

The module enables web notifications popped up by EPESI based on feedback from other modules using the tray_notification() Common method.
For the javascript I am using web notifications namespace from 
https://github.com/ttsvetko/HTML5-Desktop-Notifications
This is distributed under Apache License 2.0 and makes notifications cross-browser with an unified API.

Few notes:
- I have added the method as an installation option to Epesi Core so it can be installed, removed for testing. Actual Core installation can be considered.
- as module body must be loaded by default I append the settings to Base/Box/default.ini in the install() method. To be removed if changed to Core installation.
- existing tray_notification() methods for Utils/Watchdog, Utils/Messenger and Apps/Shoutbox were modified to suit the Base/Notify module.