changegroup.getsubset: support multiple versions Allow a version parameter to specify which version of the packer should be used

changegroup.writebundle: HG2Y support This diff adds support to writebundle to generate a bundle2 wrapper; upcoming diffs will add an option to write a v2 changegroup part instead of v1 in these bundles.

changegroup.writebundle: provide ui The next diff will add support for writing bundle2 files to writebundle, but the bundle2 generator wants access to a ui object. This changes the signature and callsites to pass one in.

test-module-imports: use test-repo requirement

largefiles: don't rehash largefiles in updatelfiles if standin hash changed Standins are read before and after an update/merge, and all the standins that changes are handed to updatelfiles for getting their corresponding largefiles updated. updatelfiles would then hash the largefile and see if it already matched the new expected hash. If so, it would skip the update. If different, the largefile would be updated. It would happen very rarely that the largefile happened to match the new hash (and thus not the old one) and the hashing would thus be pointless ... and hashing is not cheap. Instead, when it is known that the standin hash changed (from an update), just update the standin unconditionally. If the largefile was "unsure" before the update, it was hashed at that point, so we know there is nothing to preserve. (Also, the hashing in updatelfiles was not used to preserve changes, but only to be lazy about updating the largefile, so nothing is lost by not doing this extra hashing.) There might be rare situations where we now will update largefiles that didn't have to be updated, but in all relevant cases (?) this will improve performance. Updates on a repo with some big largefiles has been seen to go from 9.19 s to 6.8 s - that is 26% less painful.

largefiles: show progress when checking standin hashes in outgoing changesets This checking can take a huge amount of time and we should give user a hint that something is going on.

unbundle: support bundle2 files This adds support for bundle2 files to the unbundle command.

pullbundle2: extract addchangegroup result combining into its own function This will also be used for 'hg unbundle'