The 'text' and 'windowText' were both used like they were the same
thing, which they currently are but don't have to be.
Now migrate the various cases where to we use 'text' to 'windowText'.
This choice is made because the Label object uses windowText by default.
In future we might want to make the 'text' one have a slightly different
color. Its still used in Qt components like the popup menu.
This improves the TextButton to be more re-usable and have an arrow to
make it clear it actually is a button.
Added a sub-text as well.
This made it really easy to make an About page with some subpages or
external links.
Also increased the top-header from 40 to 50 'pixels'.
tomFlowee