New upstream release

- update to version 2.9.1
* coal: hgweb style adds extra blank line in file view (issue4136)
* hg.openpath: use url.islocal to tell if the path is local (issue3624)
* hgweb: hack around mimetypes encoding thinko (issue4160)
* hooks: only disable/re-enable demandimport when it's already enabled
* merge: add "other" file node in the merge state file
* merge: audit the right destination file when merging with dir rename
* merge: don't overwrite file untracked after remove, abort with 'untracked files'
* merge: record the "other" node in merge state
* pathencode: eliminate signed integer warnings
* pull: close peer repo on completion (issue2491) (issue2797)
* purge: avoid duplicate output for --print (issue4092)
* rebase: do not try to reactivate deleted divergent bookmark
* resolve: use "other" changeset from merge state (issue4163)
* verify: do not prevent verify repository containing hidden changesets (forwarded request 225867 from develop7)