Revert "Consolekit: sync & unmountall before reboot / shutdown"

This reverts commit f79168770fefa9754f01dd8a582732d8ae70e6e6.
Revert "Consolekit: implement *safe* shutdown / reboot"

This reverts commit 7a1055769fbe3eae024b61c11b1192104724b425.
busybox: re-add 'safe shutdown / reboot'
ConsoleKit: re-add 'safe shutdown / reboot'
xbmc: init: add 'safe shutdown / reboot'. we need this for RPi