This update for cockpit fixes the following issues:

- disable selinux on leap versions without selinux
- set libexec dir to %_libexecdir (boo#1223533)

- new version 316:
  * cockpit.js API: Fix format_bytes() units

- new version 315:
  * Networking: Show additional ports for each firewall zone
  * Networking: List Firewall active zones when unprivileged
  * Inline documentation
  * Support for transient virtual machines
  * UEFI for virtual machines
  * Unattended virtual machines installation
  * Localize times
  * Better support for various TLS certificate formats
  * Overview: Add CPU utilization to usage card
  * Dashboard: Support SSH identity unlocking when adding new machines
  * SElinux: Introduce an Ansible automation script
  * Machines: Support 'bridge' type network interfaces
  * Machines: Support 'bus' type disk configuration