a11y: emit entry signals immediately

We want to emit signals when stuff happens, not sometime later. That way
we can also catch the correct text that was deleted.

https://bugzilla.gnome.org/show_bug.cgi?id=659445

gtk/a11y/gtkentryaccessible.h

@@ -38,10 +38,6 @@ struct _GtkEntryAccessible
 {
   GtkWidgetAccessible parent;
 
-  gint position_insert;
-  gint position_delete;
-  gint length_insert;
-  gint length_delete;
   gint cursor_position;
   gint selection_bound;
 };