Added new categories and tags

Plus:
- Updated all links
- Updated all pages to Markdown
- Added new quote from ERS
Merge branch 'master' of https://github.com/GSA/search.digitalgov.gov

Conflicts:
	_posts/2011-09-15-august-2011.md
	_posts/2012-04-18-releases.md
	_posts/2012-05-11-releases.md
	_posts/2012-06-19-releases.md
	_posts/2012-07-03-releases.md
	_posts/2012-07-13-releases.md
	_posts/2012-08-08-releases.md
	_posts/2012-08-15-releases.md
	_posts/2012-08-22-releases.md
	_posts/2012-09-21-releases.md
	_posts/2012-09-28-releases.md
	_posts/2012-10-19-releases.md
	_posts/2012-11-02-releases.md
	_posts/2012-11-16-releases.md
	_posts/2012-12-14-releases.md
	_posts/2013-01-04-releases.md
	_posts/2013-01-11-releases.md
	_posts/2013-01-25-releases.md
	_posts/2013-02-01-releases.md
	_posts/2013-02-08-releases.md
	_posts/2013-02-22-releases.md
	_posts/2013-04-05-march-2013.md
	_posts/2013-04-05-releases.md
	_posts/2013-05-03-april-2013.md
	_posts/2013-05-10-releases.md
	_posts/2013-05-31-may-2013.md
	_posts/2013-06-21-june-2013.md
	_posts/2013-07-31-july-2013.md
	_posts/2013-08-31-august-2013.md
	_posts/2013-09-30-september-2013.md
	_posts/2013-10-31-october-2013.md