high dpi issues wiki page

[Kai Uwe Broulik]

Hi,

As the original author of this page I'd say let's kill it.

Most tips and tricks for applications are obsolete with Qt's built-in high dpi support and in Plasma 5 we had high dpi support ‎as a high priority anyway. 

If we were to keep something like this, it should be instead tips how to make an app ready for Qt's high dpi stuff and what to consider when doing eg. QPainter painting.

Cheers,
Kai Uwe