Stopping X11 maintenance after Plasma 5.12

[Martin Flöser]

Hi all,

this is just an early heads-up that I decided to personally stop any 
work related to X11 after Plasma 5.12. That is I will not add any new 
X11 specific code to e.g. KWin and I will not fix any bugs related to 
X11. I'll do that for 5.12, but not for 5.13. KWin itself is something I 
already consider feature frozen for X11, so any changes brought in after 
5.12 will get an automatic reject by me.

Cheers
Martin