Added opengraph_author_object filter hook on the author object

- Some white space changes for consistency with the rest of the file.

Part 1 of a solution for:
GigaOM/gigaom#4904

See also:
https://github.com/GigaOM/gigaom-plugins/pull/2879
https://github.com/GigaOM/go-local-coauthors-plus/pull/29