m.b.atom: Add support for the published and category properties

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
Merge branch 'master' into asylum
asylum: Revert atom base uri to http

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
asylum: Improved Atom template

Madness can now handle published and category elements, add those to
the template too, along with copyright notices.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>