GtkPlacesSidebar: Show unmounted bookmarks

The GtkFileInfo is only used if there's no bookmark name,
or to get the icon for the remote share or local folder.

https://bugzilla.gnome.org/show_bug.cgi?id=711548
Add print to PDF to recent manager

Printing a file with to PDF/etc. with the virtual printer option doesn't add
the file to the list of recently used files. It should be there, so I can
easily access it.

https://bugzilla.gnome.org/show_bug.cgi?id=668598
broadway: Improve touch events

We now respect core pointer grabs, and we do the pointer emulation
detection on the browser side.
Updated Polish translation
Add a GtkSetting for 'shell-shows-desktop'

Add a GtkSetting for whether the desktop shell is showing the desktop
folder icons.

This is on by default because most desktop shells do show the icons on
the desktop.  We already have a patch in gnome-settings-daemon to bind
this to the org.gnome.desktop.background show-desktop-icons GSettings
key which is off by default on GNOME.

https://bugzilla.gnome.org/show_bug.cgi?id=712302
GtkPlacesSidebar: use shell-shows-desktop setting

Use the just-added shell-shows-desktop GtkSetting to determine if we
should also show the "Desktop" folder in the places sidebar.

https://bugzilla.gnome.org/show_bug.cgi?id=712302
GtkWidget: Add margin-start and margin-end properties

Add margin-{start,end} and gtk_widget_{get,set}_margin_{start,end}
and drop margin-{left,right} and gtk_widget_{get,set}_margin_{left,right}.

margin-{start,end} handle right also in RTL.

https://bugzilla.gnome.org/show_bug.cgi?id=710238