Spelling fixes supplied by Rob W. W. Hooft. All these are fixes in either
comments, docstrings or error messages. I fixed two minor things in
test_winreg.py ("didn't" -> "Didn't" and "Didnt" -> "Didn't").

There is a minor style issue involved: Guido seems to have preferred English
grammar (behaviour, honour) in a couple places. This patch changes that to
American, which is the more prominent style in the source. I prefer English
myself, so if English is preferred, I'd be happy to supply a patch myself ;)
diff --git a/Python/ceval.c b/Python/ceval.c
index bcdd98f..3225685 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -2769,7 +2769,7 @@
 			/* Call the base's *type*, if it is callable.
 			   This code is a hook for Donald Beaudry's
 			   and Jim Fulton's type extensions.  In
-			   unexended Python it will never be triggered
+			   unextended Python it will never be triggered
 			   since its types are not callable.
 			   Ditto: call the bases's *class*, if it has
 			   one.  This makes the same thing possible