Stop using G_TYPE_INSTANCE_GET_PRIVATE completely

See merge request !402

font chooser: Properly include freetype headers

Closes #1432

See merge request !413

The values have been 0/0 for a long time now, so just drop the
GtkAllocation argument and replace it with width and height.

Fixes the foreigndrawing demo.

The size definitely changes, otherwise ->size_allocate does not get
called.

ReadAll now accepts an array of patterns.

eventcontrollerscroll: Conditionally propagate ::scroll

Closes #45

See merge request !250

Currently, gtk_event_controller_scroll_handle_event() always returns
TRUE if it is handled, which stops the propagation of the event. If
there’s a single GtkEventControllerScroll in the widget hierarchy, that
means that no others will run, depending on the propagation phase. In
Nautilus, this can be observed when adding a scroll controller to the
GtkScrolledWindow (ctrl-scrolling controls the zoom level) - either the
scrolling or the zooming breaks.

Fixes #45

freetype headers should be included via <ft2build.h> and then
indirectly via FT_*_H macros.

Fixes issue #1432.

This is all being done already be the add_class/remove_class calls
before.

That's already the css name of all labels.

We only pass 0 anyway.

- refresh with a light bg color, use the new color palette

- don't try deriving from bg_color, osd should be consistent
  for light & dark.

FIxes issue #1449

Gives the same background color to all separators descending from a
title bar than to its direct childrens.

This prevents separators which are in a titlebar but not direct children
from the widget with the titlebar style class from being almost
transparent and hence it prevent them from revealing the clear color of
the window's titlebar (black).

#1231

Adwaita: draw insensitive progressbars

See merge request !360

Adwaita: use new HIG colors

See merge request !407

- blue selection color, success & destructive colors updates
- blueish tint for dark

Addresses issue #1443

As discussed in !388.

176 -> 144 bytes

... symbolic icons.

So rotating offscreen nodes works.

We don't need it in the instance struct since we only set it up and then
access it in its signal callbacks.

This is better than nothing at all. The wording is taken from Carlos's
commit message when he added this shortly before 3.12 (but skip Since).
Skip the bit from his commit message explaining what this replaced; we
don't need to say all the less good things our convenience API replaces.