copies: remove redundant filtering of ping-pong renames in _chain() We already handle the ping-pong rename case in the filtering step, so there's very little point in doing it in the chaining loop (ping-pong renames are very rare, so I'm not worried about the cost of adding it and then removing it again). Differential Revision: https://phab.mercurial-scm.org/D6344

repair: reword comments that I noticed while working on source formatting I think this is clearer, and one will also keep us from upsetting check-code when other formatting cleanups happen. Differential Revision: https://phab.mercurial-scm.org/D6339

gendoc: nest command headers under category headers Differential Revision: https://phab.mercurial-scm.org/D6329

minirst: support subsubsubsubsections (header level 5) with marker '''' Differential Revision: https://phab.mercurial-scm.org/D6328

gendoc: guarantee that all commands were processed The new logic renders the commands belonging to each category in turn. Commands with an unregistered category are at risk of getting skipped because their category is not in the list. By comparing the list of all commands to a log of processed commands, we can detect commands with unregistered categories and fail with an error message. Differential Revision: https://phab.mercurial-scm.org/D6327

gendoc: group commands by category in man page and HTML help Make Mercurial's man page and HTML help group commands by category, and present the categories in a helpful order. `hg help` already does this; this patch uses the same metadata. This patch uses the same header level for command categories and for commands. A subsequent patch will push the command headers down one level. Differential Revision: https://phab.mercurial-scm.org/D6326