removed print function from global ML name space, to reduce risk of surprises;

--- a/src/Pure/ML-Systems/polyml_common.ML	Mon Jun 01 13:32:54 2009 +0200
+++ b/src/Pure/ML-Systems/polyml_common.ML	Mon Jun 01 15:25:59 2009 +0200
@@ -17,6 +17,8 @@
 
 val forget_structure = PolyML.Compiler.forgetStructure;
 
+val _ = PolyML.Compiler.forgetValue "print";
+
 
 (* Compiler options *)