generalize callbacks to build ids, not job+name

this will allow for one-off builds to later exercise the same callback
hooks.

various db calls are generalized to give and take a build ID rather than
job + name. more will probably be converted in the future.

regression: aborted builds will show with status 'errored'. the real fix
will be to have the turbine report status 'aborted' when builds are
aborted.