Revert "raise fullscreen windows on top of all other X11 windows"

This reverts commit 0659a0d98ca98fcd134c277c6a61ca3c9a04544e.

It was a fix for dzen2 setups, but broke several other use cases.
Because dzen2 is not really important since most people use i3bar
nowadays, let’s revert this.

fixes #1062
fixes #1068
fixes #1070
Merge branch 'revert-fullscreen'
Bugfix: update root geometry on output changes for “fullscreen global” (Thanks kaersten)

fixes #1064
Merge branch 'fix-fullscreen-global'
Bugfix: don’t flatten tabbed/stacked containers

fixes #1053
Merge branch 'fix-flattening'