Fix most trivially-findable print statements.

There's one major and one minor category still unfixed:
doctests are the major category (and I hope to be able to augment the
refactoring tool to refactor bona fide doctests soon);
other code generating print statements in strings is the minor category.

(Oh, and I don't know if the compiler package works.)
diff --git a/Lib/rexec.py b/Lib/rexec.py
index 665f294..e5ceb72 100644
--- a/Lib/rexec.py
+++ b/Lib/rexec.py
@@ -552,7 +552,7 @@
         try:
             fp = open(args[0])
         except IOError as msg:
-            print "%s: can't open file %r" % (sys.argv[0], args[0])
+            print("%s: can't open file %r" % (sys.argv[0], args[0]))
             return 1
     if fp.isatty():
         try: