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.)

Lib/gzip.py

@@ -470,7 +470,7 @@ def _test():
                 g = sys.stdout
             else:
                 if arg[-3:] != ".gz":
-                    print "filename doesn't end in .gz:", repr(arg)
+                    print("filename doesn't end in .gz:", repr(arg))
                     continue
                 f = open(arg, "rb")
                 g = __builtin__.open(arg[:-3], "wb")