Merge pull request #241 from pwendell/master

Update broken links and add HDP 2.0 version string

I ran a link checker on the UI and found several broken links.

(cherry picked from commit 1f4a4bccf3cf7376c634bad2ebadfdd4c6f78195)
Signed-off-by: Patrick Wendell <pwendell@gmail.com>
Use consistent CHANGES.txt format
Merge pull request #243 from pwendell/branch-0.8

Improve CHANGES.txt file in branch 0.8

This makes the format consistent with the 0.8.0 release which was nicer.