Add nagios performance data to output for nagios plugins

[Derek Downey]

In order to utilize the nagiosgraph plugin for Nagios, plugin output seems to require the performance data be in the output of the plugin. Here is the nagios documentation on it: http://nagios.sourceforge.net/docs/3_0/perfdata.html

from a couple of tests (those from the pmp-check-mysql-status documentation) it graphs fine simply by duplicating $NOTE after a pipe and removing the whitespace from the duplicate $NOTE in the case of 'OK' status.

I've attached a patch for the pmp-check-mysql-status tool.

PS: I say "seems to" because there might be a way around this within nagios that I don't know about, that wouldn't require modifying the percona plugins.