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/unittest.py b/Lib/unittest.py
index 9163e84..cde310f 100644
--- a/Lib/unittest.py
+++ b/Lib/unittest.py
@@ -759,8 +759,8 @@
         self.runTests()
 
     def usageExit(self, msg=None):
-        if msg: print msg
-        print self.USAGE % self.__dict__
+        if msg: print(msg)
+        print(self.USAGE % self.__dict__)
         sys.exit(2)
 
     def parseArgs(self, argv):