Updated params to account for oracle linux.

We should analyze the $::osfamily fact to define $nx_daemon_user.  Support for
$::operatingsystem remains but is greeted with a deprecation warning that
suggests upgrading to factor >= 1.7.2.

Corrected spec failures in redhat.pp when evaluating an undef
$::lsbmajdistrelease.  Now the variable must be defined before comparison.