Allow defining a site/post author as a simple key value pair (name: Ben) or, as an object, e.g.:

author:
  name: Ben
  uri: "http://ben.balter.com"
  email: [email protected]

In the first case, we'd just set author.name to Ben, and in both cases, only output the field (which is supported within the atom spec) if present.