narrow: update TODO.rst now that we share format with sparse
The narrowspec format was unified with the sparse format in
f64ebe7d2259 (narrowspec: use sparse.parseconfig() to parse narrowspec
file (BC), 2018-08-03).
Differential Revision: https://phab.mercurial-scm.org/D4904
Integration with the share extension needs improvement. Right now
we've seen some odd bugs.
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.