manifest: add treemanifestctx class...
manifest: add treemanifestctx class
Before we start using repo.manifestlog in the rest of the code base, we need to
make sure that it's capable of returning treemanifests. As we add new
functionality to manifestctx, we'll add it to treemanifestctx at the same time.
We also comment out the manifestctx p1, p2, and linkrev fields for now, since
we're not implementing them on treemanifest yet.