[feature request] Cookie support

[Keith Beckman]

I noticed that cadaver very purposely doesn't include cookie support
(http://www.webdav.org/cadaver/history.html, release 0.14.1). However,
several commercial servers, including Novell's oneNet NetStorage,
require session cookies for use (NetStorage maintains a persistent 401
if proper Basic credentials are offered without the session cookie).

While philosophical issues about the WebDAV RFC abound -- and this may
indeed be considered a server bug -- cookies are part of HTTP and WebDAV
is considered an extension to HTTP; so there's a philosophical point to
be made that cookies _are_ part of WebDAV simply by inclusion of all
elements of a subset by a superset. cadaver's current behaviour,
whatever the philosophical issues around cookie support, nonetheless
fails to live up to the Robustness Principle ("/Be conservative in what
you do, be liberal in what you accept from others/.").

cadaver is unusable with several common commercially-available servers,
and its utility is not simply limited by that, but is in environments
which use such servers (my university, for example) exactly nil. cadaver
does not support possibly-nonstandard but accepted server behaviour,
which, for a client, is pointless.

The fact that support was accidentally added and later removed shows
that adding this support should be trivial, as it's supported by the
underlying HTTP library (libneon). I hope you'll consider restoring
cookie support to cadaver so this utility can be useful not only in the
ideal, RFC-compliant-sunshine world, but also in the real world,
populated by real servers that may not always abide by the letter of the
RFCs.

Thanks! and Cheers!
     Keith Beckman