isn't running

Pass the process id of the manager as a parameter to "wait_for_pid"
and if the manager isn't running, then do not continue to wait.

Also, capture the error message of our process-existence test, 
"kill -0", as we expect errors and shouldn't pass them to the user.  
Additionally, be a bit more descriptive of what the problem is.


support-files/mysql.server.sh:
  Test that the PID-file's manager is running while we're waiting for
  something to happen with the pid-file.
  
  Capture the error message of our process-existence test, "kill -0",
  as we expect errors and shouldn't pass them to the user.
  Additionally, be a bit more descriptive of what the problem is.