narrow: delete a stale TODO about not sending groups the client already has 2c5835b4246b changed the changegroup generation to not send treemanifests for directories the client had before widening. As that commit mentions, we had already stopped before that commit to send the changelog and filelogs for files the client already had. Differential Revision: https://phab.mercurial-scm.org/D9898

copies: add an devel option to trace all files Filelog based copy tracing only trace copy for file that have been added. This is a trade off between skipping some rare copy case in exchange for avoiding atrocious-to-the-point-of-unusable performance. The changeset centric copy tracing does not need this trade off and naturally trace all copy, include the one involving non-new files. In order to ease the comparison from both algorithm, we add a small devel option to trace copy for all files in the target revisions. Differential Revision: https://phab.mercurial-scm.org/D9796

revlog: prepare pure parser for being overloaded The current class uses module-level variables which don't allow for reusing the current logic for a slightly different revlog version. Differential Revision: https://phab.mercurial-scm.org/D9903