Killed the <> operator.  You must now use !=.

Opportunistically also fixed one or two places where '<> None' should be
'is not None' and where 'type(x) <> y' should be 'not isinstance(x, y)'.
diff --git a/Lib/wsgiref/headers.py b/Lib/wsgiref/headers.py
index 934a645..0908f60 100644
--- a/Lib/wsgiref/headers.py
+++ b/Lib/wsgiref/headers.py
@@ -63,7 +63,7 @@
         Does *not* raise an exception if the header is missing.
         """
         name = name.lower()
-        self._headers[:] = [kv for kv in self._headers if kv[0].lower()<>name]
+        self._headers[:] = [kv for kv in self._headers if kv[0].lower() != name]
 
     def __getitem__(self,name):
         """Get the first header value for 'name'