Notifier Refactoring (NotifierContentPane)

[oliverp]

As a developer i need a clear and crispy API for the notifier component. Currently the notifier is binded to the body and is missing the connection to the echo component.

Idea:

Make the notifier API accessible through a specialized ContentPane (NotifierContentPane).

Target code:
contentPane.show(notification);

The Notifier is currently a kind of hack because of:

it can only work if it is a child of the ContentPane (echo3 restriction)
there maybe multiple instances per application but all of them share the "body" html element
notification-messages are not "send" to the notifier. Instead all notifier properties are replaced. This update event triggers the "show a new notification" method in the actual jquery notifier

The refactoring shall include:

The notifier-api is part of a specialized "ContentPane". Each ContentPane has its own stack of "NotificationMessages". This allows e.g. Notifications inside windows etc.
The notification-message is a complex object that is sent "as value" to the notifier