Log Message:
Update Mercurial to 4.7:

- stop/abort/no-commit support for "graft"
- confirm/dry-run support for "rebase"
- "export" of bookmarked branches
- "acl" extension can support bookmarks
- optional word-diff support
- smarter parent selection for changes in merges by default
- sparse-revlog option to allow smaller manifests for very big
  repositories
- fix compression handling on ssh streams, noticable with pullbundles
- various other bugfixes