scrollview in dialog

[ghost]

There are still bugs. If you're interrested I create a second pull request, when I solved it.

Thanks for your grat app. I've found it on F-Droid.

I changed the layout of the main dialog. This will also solve #9 (if I understood right). I had the problem also, when the content consists of long text. This is also the reason why title and content have now their own column.

Here a screenshot from my changes: