convert: introduce hg.revs to replace hg.startrev and --rev with a revset The existing knobs for controlling which revisions to convert were often insufficient. Revsets is a shiny hammer that provides a better solution. Revsets has been introduced in --rev handling in a lot of other places while being more or less backwards compatible. Doing the same here would be a much more elegant ... but that would unfortunately not work in this case. "--rev 7" used to mean revision 0 to 7 - it would be an unacceptable change if it suddenly just meant revision 7. Instead we introduce a new configuration setting. It will only work for Mercurial repositories so adding a new commandline option for it would not be a nice solution. There is no way to use the fancy deprecation markup for configuration settings so we just remove the documentation of hg.startrev.