shelve: add logic to preserve active bookmarks This adds an explicit active-bookmark-handling logic to shelve. Traditional shelve handles it by transaction aborts, but it is a bit ugly and having an explicit functionality seems better.

metadataonlyctx: speed up sanity check Previously the sanity check will construct manifestctx for both p1 and p2. But it only needs the "manifest node" information, which could be read from changelog directly.

revset: factor out linerange processing into a utility function Similar processing will be done in hgweb.webutil in forthcoming changeset.