proxy-vfs: also proxy the `audit` attribute
In the previous changeset, we had to do a little dance to access the useful
`audit` attribute. We now provide a proper accessors to it.
We don't update the code in `perf.py` because it has to remain compatible with
older version of Mercurial. This will just be nicer in the future.
skip ignored directories if -i or --all not specified
$ hg init t
$ cd t
$ echo 'ignored' > .hgignore
$ hg ci -qA -m init -d'2 0'
$ mkdir ignored
$ ls
ignored
$ hg purge -v --no-confirm
$ ls
ignored