Update docs and pages from conversation at IIW 2014
remove duplicate line
minor changes and cleanup
add "Covert Redirect" advisory
update pingback/webmention endpoints
add link to section 4.1.5
minor wording changes to advisory
Updating MPOAuth link

MPOAuth moved from Google Code to GitHub.
Added .net client lib
Merge pull request #69 from kylehayes/patch-1

Updating MPOAuth link
Merge pull request #70 from DavidDeSloovere/patch-1

Added .net client lib
Correct Apache Amber to Apache Oltu

Apache Amber was renamed to Apache Oltu in December 2012 [1]. Correct
the names and links under OAuth 2.0 implementations.

[1]: https://mail-archives.apache.org/mod_mbox/incubator-amber-dev/201212.mbox/%3CCAAqLGLPwSEmcqPMsYk_wiCUtVbD9oZeQdFoAuL2HG5uf3f=Csw@mail.gmail.com%3E
Merge pull request #72 from charlessimpson/apache-amber-oltu

Correct Apache Amber to Apache Oltu
Update link to Ruby Oauth library
Merge pull request #73 from jcamenisch/patch-1

Update link to Ruby Oauth library
Syntax cleanup with pandoc, add https://github.com/authbucket/oauth2 and https://github.com/authbucket/oauth2-bundle.
Merge pull request #74 from hswong3i/master

Syntax cleanup with pandoc, add https://github.com/authbucket/oauth2 and https://github.com/authbucket/oauth2-bundle.