Fix validation error on home page. #1508.
Move news/index.md to news/index.html to prevent unnecessary <p> tags. #1508.
Move news/releases/index.md to news/releases/index.html to prevent unnecessary <p> tags. #1508.
Add alt tag to post author <img> tag in site. #1508.
Move .post .post-content to a <div> to maybe fix weird validation issue. #1508.
Merge pull request #1511 from mojombo/fix-validation-errors

Fix W3C Validation Errors On jekyllrb.com