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.
shell: Integrate recent view into the main window

* Allow switching between document and bookshelf
* It seems more natural as we 'toggle' between the bookshelf the
currently open document.
ev-recent-view-toolbar: Implement a different toolbar for recent view

Added a new EvRecentViewToolbar which is displayed while in
recent view, instead of the full regular toolbar.
ev-window: Integrate the recent view toolbar
ev-window: Removed the recent menu list

Since we have EvRecentView now, there is no use of the menu of recent items.
Removing it.