adjust tooltip for duplicates option

--- a/src/Tools/jEdit/src/find_dockable.scala	Fri Aug 09 20:44:46 2013 +0200
+++ b/src/Tools/jEdit/src/find_dockable.scala	Sat Aug 10 09:06:42 2013 +0200
@@ -145,7 +145,7 @@
   }
 
   private val allow_dups = new CheckBox("Duplicates") {
-    tooltip = "Allow duplicates in result (faster for large theories)"
+    tooltip = "Show all versions of matching theorems"
     selected = false
   }