Rewrote the help message to list the options instead of having
multiple paragraphs of text. Renamed PostRaw to post and added support
for the new options. Pass the new options through copy.
(main, copy, PostRaw): Add support for -u and -p.
(RequestAgent): Private specialization of LWP::UserAgent using the
-w option.
(GetRaw, PostRaw): Use it.
(main): Add -w option.