Merge remote-tracking branch 'staging'

* staging:
  dot/gitconfig.in: Don't have `git send-email' try to do threading.
  dot/gitconfig.in: Abolish the `git email' alias.
  dot/gitconfig.in: Remove output filename; force full indices.
  git/gitignore: Ignore toplevel `p/' and `p.*/' directories.
  git/gitignore: Only ignore `build' etc. if they're toplevel directories.
  git/gitignore: Deprecate `deb-build/' and `build-*/' directories.
  dot/gitconfig.in: Configure `format-patch' to do sensible things.