export is_draft, not draftN;

--- a/src/Pure/context.ML	Thu Apr 10 17:01:41 2008 +0200
+++ b/src/Pure/context.ML	Thu Apr 10 20:54:15 2008 +0200
@@ -24,7 +24,7 @@
   val is_stale: theory -> bool
   val PureN: string
   val CPureN: string
-  val draftN: string
+  val is_draft: theory -> bool
   val exists_name: string -> theory -> bool
   val names_of: theory -> string list
   val pretty_thy: theory -> Pretty.T