Fix warning
Merge pull request #28 from ascarpino/master

Fix warning
When systemd is used, use systemctl to reboot/poweroff the computer
Update PKGBUILDs.
Merge pull request #29 from ascarpino/master

When systemd is used, use systemctl to reboot/poweroff the computer
Update Xsession script copyright info.
Set seat id and virtual terminal number on the session process.
Set DESKTOP_SESSION env variable.
Clean up.