Add a page to display all articles by an author

[eternoendless]

Questions	Answers
Description?	The list of authors (/authors) is now built based on the authors declared in posts, shows names, and is ordered by most recently published. By clicking on an author name or profile picture on any page, you get to a new "author page" (/authors/[slug]) with the author's profile and all their articles.
Fixed ticket?	Fixes #763

Screenshots

All articles by author

Authors list

[kpodemski]

thanks @eternoendless :)