Set per platform nrpe home values and set arch specific values on RHEL/Fedora

This matches how package installs setup the nrpe home directory on RHEL
based systems.
Add per platform / arch values for the nagios plugins directory

RHEL 64bit needs to be in a different directory than other platforms
Merge pull request #86 from tas50/COOK-2130

Cook 2130: Use the correct plugin path / home dir values on 64bit RHEL / Fedora systems