This update for cockpit, cockpit-machines fixes the following issues:

Changes in cockpit:
- Fix libexecdir for leap and sle (boo#1223533)
- Fix systemd units folder for leap and sle (boo#1226541)

- Recommend cockpit-packagekit if zypper is installed

- new version 321:
  * Bug fixes and performance improvements
- update_version.sh: use instead of `osc service mr` to do version
  updates. updated README.packaging

Changes in cockpit-machines:

- Add initial package of version 316