Authentication article
updates to authentication article
updated title, comments from WG
added links from John Bradley, added links to external specifications
updated authentication article with new references and text
added "articles" section, moved "about" header to link to "/2/" instead, added back link to OAuth 1.0 from bottom of /2/
updated authentication article text
added index page for articles section
fixed secondary nav links
moved authentication article to subdirectory for pretty URLs
fix require paths
Merge branch 'master' of github.com:aaronpk/oauth.net