complete refactoring of the get_user_by_uri function
removed some whitespaces and added more descriptive var-names
fixed some more whitespaces
added a filter to change user
Merge pull request #8 from pfefferle/refactor-get-user-by-uri

I had a look at WP_Query but it seems that you need the query params and that is exactly why I implemented the url_to_authorid function. When using modrewrite we don't have the query-string.