I'll rework it to allow filtering by completed, successful or stable which will allow my to use the `last*Build` methods.

I see that `getLastSuccessfulBuild` in `Job.java` uses `(RunT)Permalink.LAST_SUCCESSFUL_BUILD.resolve(this);` 

Most of the other methods like `getLastStableBuild()` and `getLastCompletedBuild()` do not, they use a while loop to go through the builds.

Should these be using the `PeepholePermalink` based methods now?