Both POST() and PUT() take data in the same way

This patch routes calls to PUT() and POST() through the same channel, fixing a bug that caused PUT( $url, $hashref ) to ignore $hashref. With this fix, LWP::UserAgent's put() method will work as advertised, currently, it will ignore data passed in as hash refs and array refs.

It also corrects the number of planned tests in t/headers.t.