Arch Linux

Description:
The arch-provided unit file for tincd does not specify KillMode=none, and so tincd is killed before it gets a chance to finish shutting down (triggered by the ExecStop command). As a result, the network tinc-down script is not executed. This results in significant loss of functionality. Adding KillMode=none to the systemd unit file fixes the issue. I have attached a patch which fixes the issue.

Additional info:
* Package version: 1.0.25-2 (current)

Steps to reproduce:
* In the configuration directory of the tinc network (/etc/tinc/<network>), create the file tinc-down and make it executable.
* Add a command such as "echo testing > /var/log/tinc" to tinc-down.
* Start the tinc service using systemctl start, then stop the service using systemctl stop.
* /var/log/tinc does not exist, and the tinc-down executable has not been run as it should have when the tincd service stopped.
* Start tincd manually using "tincd -n <network> -D"
* Stop tincd manually using "tincd -n <network> -k"
* /var/log/tinc exists and contains "testing", as it should.