improve the publication factory lookup by falling back to a more generic registration if the specific factory chooses not to handle the request after all
improve interface description
removing errorneously added webtest "dependency"
update changelog
fix version pin
fix version pin
old-style self.assertRaises
Merge pull request #1 from minddistrict/master

Improve the publication factory lookup by falling back to a more generic
registration if the specific factory chooses not to handle the request
after all.

Also, fail clearly by raising an configuration error always if no
handling factory can be (instead of returning None in that case, which
is not handled properly in the callee).