Improve deprecation warnings

[ggam]

The following can be done to better advise the user about deprecated stuff:

• create a dedicated topbar section for deprecated components and move datePicker and slider there
• in the page of the deprecated component, a clearly visible message should be added indicating that the component is deprecated and preferably, an explanation of the reasons.
• log a warning when instantiating a deprecated component. This can be done on the default constructor
• deprecated components should be annotated @deprecated to instruct developers reading trough the code
• deprecated atributes should use styling. Can xtext handle this?

[stephanrauh]

As for the top menu: as long as we'll offer a solution for small and medium (iPad) screens, I'm fine with that.

Xtext can do anything :). It's just a framework we can use to generate code more easily. The code generator itself is a program written by us. Basically, it's just this folder: https://github.com/stephanrauh/JSFLibraryGenerator/tree/master/de.beyondjava.xtext.jsf/src/de/beyondjava/xtext/jsf/generator. Not much code, given how much it helps us.