Updated Belarusian translation.

(cherry picked from commit f69d58ac81a6cc1e74bf7a0d7d78a0af3db42bf5)
libgd: Added libgd to cut-n-paste

A separate commit where libgd is added to cut-n-paste. libgd is used for the bookshelf
view of recent documents.
libgd: Use cairo surfaces instead of pixbufs in gd_embed_image_in_frame
libgd: Expect a cairo surface instead of a pixbuf for the GdMainIconView cell renderer
ev-recent-view: Added bookshelf view for recent documents

* Files are added to the bookshelf only if they exists
* Use gtk_recent_info_get_modified instead of
  gtk_recent_info_get_visited for ordering the recent items.
recent-view: ev_recent_view_new should return a GtkWidget
libgd: Highlight items on mouse-hover
recent-view: Do not propagate button_press_event in recent view

Otherwise, when using single clicks the drag icon would remain
active.
[l10n] Updated Catalan (Valencian) translation
Add a configure check for hi-dpi support

In order to support hi-dpi (GDK_SCALE) we need new-enough versions
of both GTK+ and cairo. Add a configure check for the appropriate
functions and define HAVE_HIDPI_SUPPORT.

https://bugzilla.gnome.org/show_bug.cgi?id=723431
ishell: Make the about dialog non modal
shell: Update website and copyright years in about dialog
shell: Move about dialog to the app menu and make it independent from the document
shell: Use a GtkHeaderBar instead of a GtkToolbar and window decorations

Based on patch by Yosef Or Boczko.

https://bugzilla.gnome.org/show_bug.cgi?id=711078
Revert "shell: Use a GtkHeaderBar instead of a GtkToolbar and window decorations"

This reverts commit c9127524e1409d582f038439e9143695d1fadc0d.

It broke the fullscreen mode.
recent-view: Verify a path exists before adding an icon

Fixes warnings when switching from the recent view to
a document back and forth.
recent-view: Use a GtkIconView and get rid of most of libgd cut-n-paste
recent-view: Allow to open documents from recent view with the keyboard
recent-view: Do not sort the GtkTreeModel

We already sort the recent items ourselves and everytime the recent
files change we clear and fill the model again.
printing: Fix centering when shrinking to printable area but not scaling

When shrinking to printable area is selected and we don't need to scale
because the document fits in the printable area, the document is
centered applying the current scale. Since we are not going to scale in
that case, we should ignore any scale value > 1 when shrinking to
printable area.