workaround bug in node 0.4.x - res.getHeader() throws an exception when...

workaround bug in node 0.4.x - res.getHeader() throws an exception when invoked after a response is set, even though you're not mutating the response.  instead use the _headers map.

lib/wsapi/authenticate_user.js

@@ -55,7 +55,7 @@ exports.process = function(req, res) {
             path: '/wsapi/update_password',
             method: "POST",
             headers: {
-              'Cookie': res.getHeader('set-cookie'),
+              'Cookie': res._headers['set-cookie'],
               'Content-Type': 'application/x-www-form-urlencoded',
               'Content-Length': post_body.length
             }