Update to 0.7.17

Upstream changes:
New in v0.7.17 (2018/02/26)
---------------------------
* Removed changes made in bug #1044715 Provide a file history feature
  - Changes required too much memory to carry in the manifest
  - The option --file-changed in collection-status is now invalid
  - This will close bugs: #1730451, #896728, #1526557, #1550176
  - Starting a full backup will be needed to fully utilize this fix
* Fix update of Launchpad Translations.  Translations were not being picked
  up on a daily basis and we got several months behind.

(wen)