updated version to October 93

--- a/src/Pure/ROOT.ML	Wed Oct 27 13:49:35 1993 +0100
+++ b/src/Pure/ROOT.ML	Thu Oct 28 11:28:36 1993 +0100
@@ -12,7 +12,7 @@
 *)
 
 val banner = "Pure Isabelle";
-val version = "February 93";
+val version = "October 93";
 
 print_depth 1;