debugobsolete: also report the number of obsoleted changesets This seems useful to have the number of obsoleted changesets when calling debugobsolete.

transaction-summary: display the summary for all transactions Now that we records "all" changes happening in a transaction (in tr.changes) we will be able to provide better report on various changes (phases turned public, changeset obsoleted, branch merged or created, etc..) This is far too late in the cycle to play with this, but having this existing method called more widely will help extensions to play around with various options during the 4.4 cycle. Instead of calling registersummarycallback only for transactions we want, we always call it and use the transaction name to decide when to report (eg: we do not want `hg amend` to report new obsoleted changesets). Filtering on transaction name does not seems great, but seems good enough for the moment. We can change the API during the next cycle. The previous manual call during unbundling of the bundle2 "obsmarkers" part is no longer necessary and has been dropped.