fix: rename :fileset subconfig to :pattern This name was always inaccurate, since the config accepts any pattern. Hopefully so few people use this right now that it won't matter, but there will now be a warning if the old config name is used. Differential Revision: https://phab.mercurial-scm.org/D5226

fix: add a config to abort when a fixer tool fails This allows users to stop and address tool failures before proceeding, instead of the default behavior of continuing to apply any tools that didn't fail. For example, a code formatting tool could fail if you have syntax errors, and you might want your repo to stay in its current state while you fix the syntax error before re-running 'hg fix'. It's conceivable that this would even be necessary for the correctness of some fixer tools across a chain of revisions. Differential Revision: https://phab.mercurial-scm.org/D5200

perf: measure slicing time in perfrevlogrevision Slicing a sparse delta chain can be expensive. We now benchmark the associated time.