ViewSelector: remove the places & devices search provider

Remove the PlacesManager, its search provider and all associated code.
Places search is now provided by nautilus using the external search
provider API.

https://bugzilla.gnome.org/show_bug.cgi?id=683506

src/shell-util.h

@@ -10,9 +10,6 @@
 
 G_BEGIN_DECLS
 
-char    *shell_util_get_label_for_uri          (const char       *text_uri);
-GIcon   *shell_util_get_icon_for_uri           (const char       *text_uri);
-
 void     shell_util_set_hidden_from_pick       (ClutterActor     *actor,
                                                 gboolean          hidden);