Log Message:
Update to 1.18.16. From the changelog:

* Improve sorting stability.
* Prefer mktemp over tempfile as the latter displays a deprecation
  warning since debianutils 4.10. Thanks, Luke Mlsna.
* Use "command -v" rather than "which" to detect installed \ 
programs, as
  it is more portable. Thanks, Eli Schwartz.
* Improve commit messages generated by package manager changes,
  listing packages that are responsible for the changed config files.
  Thanks to emkael for the patch.
* If gc.auto is not configured, override the default to make it gc
  ten times more frequently, to avoid wasting space with loose objects.
* update-ignore: Preserve permissions from any preexisting VCS ignore file.
  Thanks, Austin Chu.
* Removed the debian directory from the upstream source package as it's
  not being maintained; see the debian package for an up-to-date one.
* debian/changelog moved to CHANGELOG and debian/copyright to COPYRIGHT.