+This is a lockfile implementation I created for use with cronjobs on
+my machine to prevent multiple copies of a job from running in
+parallel. When one job is running this code keeps a file on disk to
+indicate a lock is held. Other copies will fail to start if they
+detect this lock until the lock is released. There are provisions in
+the code for timing out locks, cleaning up a lock when a signal is
+received, gracefully retrying lock acquisition on failure, etc...
+