cmdutil: use context instead of lookup

scmutil: use context instead of lookup

localrepo: lookup now goes through context

context: use rev for changelog lookup Faster when we're doing numeric scanning

context: internalize lookup logic This allows us to avoid doing rev->node->rev lookups on silly instances like "0", which end up caching the whole nodemap.

revlog: allow retrieving contents by revision number

revlog: add hasnode helper method

merge with stable

merge with crew

tags: defer tag validation until repo.tags() is called Before, we were validating all tags for any tag operation, which meant building a (nearly) full node->tag lookup tree for most operations.