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/crashers/loosing_mro_ref.py

@@ -32,5 +32,5 @@ class X(Base):
     # there from the beginning :-)
     locals()[MyKey()] = 5
 
-print X.mykey
+print(X.mykey)
 # I get a segfault, or a slightly wrong assertion error in a debug build.