rework UI-headers example

[Tieske]

The example added in #37 creates a single large object for multiple tasks. It creates a full-screen terminal application.

It should be redesigned into multiple reusable components, that are combined to create this UI. Full-screen apps will most likely benefit from those reusable components.

Thinking about and experimenting with this is probably a good exercise to get started with the full-screen UI elements to design/develop.

[ngvt1n]

May I take on this?

[Tieske]

I'd advice all GSoC participants to have a take on this. I don't think there is a right or wrong, or even that the example will stay in the repo in the long run. I just think that playing around with it, trying to improve on the abstractions etc, is a good exercise. As you'll probably run into all the issues that full-screen UIs have.