app chooser: sync sensitivity of search button

The code setting up the button has been move a little later
in the dialog construction, with the effect that the entry
is already insensitive when we set up the binding.
Fix a typo

Thanks to Thomas A. Stillings for spotting it.
Forgotten file
Raleigh: fix a typo

titlebar is a style class, so it needs a .
header bar: squeeze the title in

Let the center widget extend into the border area, to avoid
resizing header bars needlessly. This improves the uniformity
of header bars across applications, some of which don't use
subtitles, or use custom title widgets.

https://bugzilla.gnome.org/show_bug.cgi?id=706515
https://bugzilla.gnome.org/show_bug.cgi?id=707999
Docs: use // for comments in examples

Without sgml mode, we can't escape /* as /&ast; anymore,
so just switch to // for comments in examples.
Updated Hebrew translation
Don't show an empty license tab

It is not useful to show a license tab, if there's no license
to read.  This was pointed out as a possibility in
https://bugzilla.gnome.org/show_bug.cgi?id=724411
Fix a problem with window dragging

Dragging windows was not working on widgets in the titlebar
region unless they had the window-dragging style property
set. Fix this by looking at the region for motion notify
events as well as for buton press events.
Add center widget support to GtkBox

This makes GtkCenterBox unnecessary, and at the same time
adds more features: the center widget can be expanded, and
baseline alignment is supported.
action bar: Use a regular box instead of GtkCenterBox

GtkBox now supports a centered child, so GtkCenterBox is
no longer needed here.
Adjust action ref test to new realities

The test was using a nonexisting GtkActionBar::spacing property.
Drop GtkCenterBox

Its functionality has been subsumed in GtkBox.
Add a testcase for box sizing
Fix doc build
po: Updated the POTFILES file
po-properties: Updated the POTFILE file
popover: Make gtk_popover_bind_model() public

This is needed for the C++ bindings.

https://bugzilla.gnome.org/show_bug.cgi?id=724503
Add gtk_popover_bind_model to the docs
Drop with_separators from gtk_popover_bind_model

The with_separators argument does not really make sense
for popovers, it was just copied from the menu implementation.
Drop it now, before it becomes part of the public API.