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/test/badsyntax_future9.py

@@ -7,4 +7,4 @@ def f(x):
         return x + y
     return g
 
-print f(2)(4)
+print(f(2)(4))