sort completions by plain string order;

--- a/src/Tools/jEdit/src/jedit/isabelle_sidekick.scala	Fri Dec 18 21:46:29 2009 +0100
+++ b/src/Tools/jEdit/src/jedit/isabelle_sidekick.scala	Mon Dec 21 15:13:42 2009 +0100
@@ -92,7 +92,7 @@
       case Some((word, cs)) =>
         val ds =
           if (Isabelle_Encoding.is_active(buffer))
-            cs.map(Isabelle.system.symbols.decode(_)).sort(Completion.length_ord _)
+            cs.map(Isabelle.system.symbols.decode(_)).sort(_ < _)
           else cs
         new SideKickCompletion(pane.getView, word, ds.toArray.asInstanceOf[Array[Object]]) { }
     }