graftcopies: remove `skip` and `repo` arguments The `skip` argument was added in 2ba6c9b4e0eb (rebase: fix bug that caused transitive copy records to disappear (issue4192), 2014-06-07) in order to fix https://bz.mercurial-scm.org/show_bug.cgi?id=4192. I ran tests at that commit without the `skiprev` argument and the only difference I noticed was that `test-rebase-collapse.t` failed differently, in the call that is now on line 501. Without the `skiprev` argument, that call would end up creating another commit because it tried to record an invalid copy. With the previous patch in this series, such invalid copies are no longer recorded, so it seems we don't need the `skip` argument anymore. I also removed the `repo` argument since that also becomes unused with the removal of the `skip` argument. Differential Revision: https://phab.mercurial-scm.org/D7860

Address commentary in manifest.excludedmanifestrevlog.add -
specifically we should improve the collaboration with core so that
add() never gets called on an excluded directory and we can improve
the stand-in to raise a ProgrammingError.

Reason more completely about rename-filtering logic in
narrowfilelog. There could be some surprises lurking there.

Formally document the narrowspec format. For bonus points, unify with the
server-specified narrowspec format.

narrowrepo.setnarrowpats() or narrowspec.save() need to make sure
they're holding the wlock.

The follinwg places do an unrestricted dirstate walk (including files outside the
narrowspec). Some of them should perhaps not do that.

 * debugfileset
 * perfwalk
 * sparse (but restricted to sparse config)
 * largefiles