upgrade review-dev from gerrit ver 2.4.x to ver 2.8

This patch will update gerrit on review-dev.o.o from our forked ver 2.4.x to
the upstream ver 2.8 release. The purpose is so we can test this newer version
before rolling it out to production.

gerrit upgrade documentation:
http://gerrit-documentation.googlecode.com/svn/ReleaseNotes/ReleaseNotes-2.8.html#_documentation

Change-Id: I9c4974fca4986ce8b94cd5bc4b6c87cc2920dde1
Merge "upgrade review-dev from gerrit ver 2.4.x to ver 2.8"