sparse: override __repr__ in matchers...
sparse: override __repr__ in matchers
sparse.py in FB's hg-experimental repo switched to using __repr__ for
non-sparse matchers soon after hg core started overriding __repr__ in
the matchers in match.py (because the core matchers also stopped
having "includepat" and other attributes that sparse used to depend
on). Let's finish that migration by implementing __repr__ in the
sparse matchers as well. That also lets us remove the special handling
of them in _hashmatcher().
