Please add a button to permanently fail a build

Today we noticed that https://edge.launchpad.net/~neon/+archive/ppa/+build/1382484 was infinite looping with output, which means that the slave will never decide that the build is hung, until it's out of disk space, at which point lp-buildd will fail with some other error, causing soyuz to decide that the ppa went away, and launch it on another ppa buildd.

The only solution today is to manually supersede the build record, and then to reset the looping ppa. This is, of course, suboptimal.

Please add a button to /builders/$HOST (and/or the build record itself??) to do the following:
1) mark the build superseded
2) cause the build to terminate. (for now, that involves getting to the path where we ppa-reset or so, once lp-buildd understands how to abort the build properly, then we should switch to using that path.)

It probably makes sense to even allow the owner of the ppa to kill a looping build with fire, as above.