This utility, inspired by the old SunOS 4.x intr(8) utility, will be
used to start daemons with --detach and a timeout, like this:
intr -t 5 kdc --detach || { echo failed to start kdc; exit 1 }
This will allow tests to stop having to sleep poll for "started" output
from the daemons they start, allowing them to run faster and to impose a
reasonable timeout on daemon startup.
The default timeout is 3 seconds.
