Atom 1.0 support

In all the hard work getting Feed Digest ready for launch, the early rumbles of Atom 1.0 passed me by somewhat. I've now begun work on making Feed Digest output Atom 1.0 feeds (currently 0.3), and particularly on getting Feed Digest to parse Atom 1.0 feeds. I've made a good start and Atom 1.0 feeds "should" work, if not fully. I will be doing some more tests later. I just thought I should let everyone know.. I'm on it :)