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