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/Bastion.py b/Lib/Bastion.py
index 2127f46..6a5cb5c 100644
--- a/Lib/Bastion.py
+++ b/Lib/Bastion.py
@@ -165,7 +165,7 @@
         print "accessible"
     \n"""
     exec(testcode)
-    print '='*20, "Using rexec:", '='*20
+    print('='*20, "Using rexec:", '='*20)
     import rexec
     r = rexec.RExec()
     m = r.add_module('__main__')