httprepo: use caps instead of between for compat check
We usually query the capabilities at some point anyway so this way the first roundtrip
actually does useful work.
bisect: new command to extend the bisect range (
issue2690)
When bisect ends in a merge point, and one of the parent wasn't checked,
this usually means the culprit is in a branch that wasn't scanned.
For this case we provide a new command which extends the range of the bisect
search to the common ancestor of the parents of the merge.
don't depend on features of Exception as much
BaseException.message has been deprecated, so we try to not rely on it.