Selector - Improvements

To help fago out and to get rid all the dependences I merged all my uncommitted patches into one big selector improvement patch.
The following patches are included:
#986252: Selector closing on group select
#986272: Selector close if no focus and click
#993460: Selector - Button optimization
And the newest addition:
Focus management overhaul (for which I did not open another issue):
This simplifies the code a little bit and solves the problem, when clicking on a button and then click on a non selector thing, not closing the autocomplete window.

I closed all the other issues.