Sanitize nrpe::check title parameter

It is possible to use spaces inside the title param of nrpe::check.
$title is used however as the file name the corresponding nrpe
configuration file This has already resulted once in false alerts
and will probably do so again. Prevent this by sanitizing and munging
all non-alphanumeric characters from the file name

Change-Id: I8d813f316272024ef5f826139ac26824a00be6ce
Merge "Sanitize nrpe::check title parameter" into production