EvSidebarThumbnails: render thumbnails correctly for hi-dpi displays

Render thumbnails with resolution from gtk_widget_get_scale_factor() and
recreate them when the scale change. Make the thumbnail-rendering helper
functions create a hi-resolution surface when the widget has a scale
factor.

https://bugzilla.gnome.org/show_bug.cgi?id=723431
libview: Fix g_return condition in set_device_scale_on_surface()

Fail when device scale is not 1 if hidpi is not available, we were doing
the opposite.
Remove the  Next-Page and Previous-Page buttons from the toolbar.

Move the actions to the View menu.
Also move the Last Page and First Page to the View menu.

https://bugzilla.gnome.org/show_bug.cgi?id=732289
Remove unused ev_toolbar_create_button and ev_toolbar_create_button_group

https://bugzilla.gnome.org/show_bug.cgi?id=732289
"<Ctrl>Home/End" scroll to the start/end of the document

Before they scroll to the first/last page. This is now managed
by the view, instead of the window.

https://bugzilla.gnome.org/show_bug.cgi?id=724273
libview: Emit accessible focused-changed signals for form fields

https://bugzilla.gnome.org/show_bug.cgi?id=733662
recent-view: Integrate recent view in the shell

Given the restrictions of GtkHeaderBar for reparenting, we must
implement multiple modes for the toolbar, which can be customized
for Recent View, Full Screen, Preview and Document (normal).

For now, Full Screen, Preview and Document are the same.

https://bugzilla.gnome.org/show_bug.cgi?id=633501
shell: Remove menu for recent items

Recent menu has been replaced by a bookshelf-like interface.

https://bugzilla.gnome.org/show_bug.cgi?id=633501