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/sre_constants.py

@@ -258,4 +258,4 @@ if __name__ == "__main__":
     f.write("#define SRE_INFO_CHARSET %d\n" % SRE_INFO_CHARSET)
 
     f.close()
-    print "done"
+    print("done")