Bug 1870803 introduced a transition to window activeness visuals. But
the lowered opacity breaks the z-index hackery we use to let
window-controls show through nav-bar.
This patch basically undoes the changes from bug 1870803
Also some cleanup for menupopup_forced_color_schemes.css for remove some
old and unused variables.
This just adds media query versions to files - old ones should be
removed at some point
Flexbox model will replace old xul box as the default display model so
this patch adds support for that in a whole bunch of styles.
A lot of style rules are marked as "Fx < 112 compatibility" rules and
those can be removed when 112 hits release.
If native titlebar is enabled the rules would move tabs and navbar
partially below native titlebar. Those rules are not needed anyway
with native titlebar since window controls are in native titlebar.
This way we can handle maximized windows not having the other drag space
like Firefox does normally. This patch additionally adds window control
width values for Win7 Win8 and linux