shellEntry: Make the entry have a fake focus state when a context menu is open

This means that right-clicking on an entry shouldn't visibly change the theme,
which is unexpected. Make sure that closing the menu refocused the entry, too.

https://bugzilla.gnome.org/show_bug.cgi?id=683509

js/ui/shellEntry.js

@@ -76,6 +76,12 @@ const EntryMenu = new Lang.Class({
             this.actor.grab_key_focus();
 
         this.parent();
+        this._entry.add_style_pseudo_class('focus');
+    },
+
+    close: function() {
+        this._entry.grab_key_focus();
+        this.parent();
     },
 
     _updateCopyItem: function() {