revsets: add branchpoint() function The branchpoint() function returns changesets with more than one child. Eventually I would like to be able to see only branch points and merge points in a graphical log to see the topology of the repository.

vfs: use fchmod for _fixfilemode On general principle, we should use fchmod instead of chmod to avoid security pitfalls, although none is likely possible here.

tests: correctly report a test killed by a signal