new default for 3.12
background: fix nighttime variant

- alignment
- firefly
tabs: provide a :hover state
CSD: bring back borders.

- cool hack by lamefun - use box-shadow to create a border
  that respects the rounded corners of CSDs
text-button: add an extra px of vertical padding

This makes them the same height of image-buttons. Original patch
by Paolo Borelli.

https://bugzilla.gnome.org/show_bug.cgi?id=721622
tabs: separators for reorderable tabs

https://bugzilla.gnome.org/show_bug.cgi?id=722366
Make box and grid transparent when insensitive

New Gtk started drawing the background for this containers and we have
*:insensitive wildcard rule which matches and causes problems.
Add them to the special cases along with image and label.
Maybe at some point we should remove the wildcard rule and do proper styling
for each widget

https://bugzilla.gnome.org/show_bug.cgi?id=721623
headerbars: soften the bottom bevel
Smooth title button separator

https://bugzilla.gnome.org/show_bug.cgi?id=722563
Use alpha instead of grey baseline for outlines

- patch by lamefun

https://bugzilla.gnome.org/show_bug.cgi?id=722563
build: separator was missing rendered assets
wm_border: typo
Make the through of the active switch consistent with other throughs

The new convention is that inset panels are nearly flat with a faint shadow,
make GtkSwitch respect it too

https://bugzilla.gnome.org/show_bug.cgi?id=722606
Fix missing shadows in active linked buttons

https://bugzilla.gnome.org/show_bug.cgi?id=722609