Libvpx buildbot waterfall.

I think I found a decent way to avoid duplicating the whole configuration for the libvpx waterfall. It's not perfect but it works. I still haven't figured out what the best way to manage the slaves would be however, since they will need to know which master to connect to, or they'll pick the default they're configured for in slaves.cfg, which is the WebRTC waterfall (can be overridden with the TESTING_MASTER property, but that's only to be used for development and testing.

BUG=None
TEST=Tested on local master and slaves.

Review URL: https://webrtc-codereview.appspot.com/595005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@2310 4adac7df-926f-26a2-2b94-8c16560cd09d
13 files changed