- update from 0.04 to 0.05
- BACKWARDS INCOMPABILITY:
  Removed XML::Atom::Entry::get_links and XML::Atom::Feed::get_links,
  in favor of new link() method in both classes, which returns a list
  of XML::Atom::Link objects. Also, add_link() now expects an
  XML::Atom::Link object instead of a hash reference.
- BACKWARDS INCOMPABILITY:
  Renamed XML::Atom::API to XML::Atom::Client.
- Added XML::Atom::Link, an encapsulation of the <link> tag in a feed
  or an entry.
- Added XML::Atom::Server, an implementation of an Atom core server
  (to be subclassed for implementation-specific methods).
- Fixed feed auto-discovery to work with all client tests at
  http://diveintomark.org/tests/client/autodiscovery/
- Added (and documented) XML::Atom::Feed->find_feeds, to return all
  of the Atom feed URIs on a page given a URI.
- Fixed issue with PasswordDigest in API (use sha(), not hex(sha())
  for generating password digest).
- Stream parameter to XML::Atom::Entry::new and XML::Atom::Feed::new
  is now optional; if passed only one parameter, it's assumed to be
  the Stream parameter.
- Fixed bug in XML::Atom::Content::as_xml (it didn't work).