Since sudo 1.7.4, the timestamp directory has moved from /var/run/sudo to
/var/db/sudo, lib or adm (in that order). See also the sudo changeset
http://www.sudo.ws/repos/sudo/rev/8c9440423d98
Keeping the "old" one (/var/run/sudo) for a while for those systems where
sudo has not been updated yet (change is since 1.7.4, Jul 14 2010).
Signed-off-by: Sven Vermeulen <sven.vermeulen@siphos.be>