Added a kill for the p4d_stop function in case p4d doesn't shut down.
In the process of testing this, I discovered that using $P4DBIN in this
case was a bug that didn't work when running in case insensitive mode because
the executable doesn't match what is actually running since we end up
calling p4d from /p4/common/bin. Corrected the grep so that it would match
in either case.