aggressivemergedelta: document rename and move to `revlog` section The config does not follow our naming guideline and "Aggressive" is probably a word to keep away from users. The option does not truly fit in the `format` section. It can be turned on and off for existing repository without much consequence regarding compatibility. A new `revlog` option is created to control behavior related to revlog writing and reading. We can see multiple other config options that could be migrated there. * format.maxchainlen * experimental.mmapindexthreshold * experimental.sparse-read.density-threshold (in an updated form) * experimental.sparse-read.min-gap-size (in an updated form) In addition, we can foresee at least a couple of sparse-revlog related option coming too (to reduce delta chain length and increase snapshot reuse) These two extra options might fit there too. Unless we want to create a section dedicated to caches and performance. * format.chunkcachesize * format.manifestcachesize For now, we only migrate `optimize-delta-parent-choice` since it is getting out of experimental. It is too close to the release to move the other one. In addition, we still lack proper the prioritization of alias that would help renaming them without bad consequence for users. (Not fully happy about the `revlog` name but could not find better).

aggressivemergedeltas: rename variable internally The "aggressivemergedeltas" name is not great. First, it is quite long, second, we would rather have less "Aggressive" names within the project. We are about to rename the config option, so it seems the appropriate time to rename the internal variable.

config: document the purpose of the `format` config section The config section now have a top level documentation to clarify its intend and usage. In particular, user are now explain when the option are taken in account and how to convert repository. There are an handful of experimental options in this section that does not match its definition. They should be relocated to other section before getting out of experimental. (see next changeset for one example).

macosx: fixing macOS version generation after db9d1dd01bf0 With the Python3 change, the string is now something like version = b'4.6.2+848-88be288e8ac1' where it was previously just: version = '4.6.2+848-88be288e8ac1' Differential Revision: https://phab.mercurial-scm.org/D3964