<Install script> - Fix RHN priority/exclude settings

yum-config-manager does not work properly on RHN channels, instead you
need to update /etc/yum/pluginconf.d/rhnplugin.conf for RHN channels
Merge pull request #31 from detiber/fixrhnconfig

<Install script> - Fix RHN priority/exclude settings
Use pam_succeed_if with pam_namespace

Use pam_succeed_if to check that the user's shell is set to
/usr/bin/oo-trap-user and only require pam_namespace if it is.

In this manner, we target our polyinstantiation configuration to gear
users only.  The old, less-targetted approach has been causing problems
in some environments where polyinstantiation was not desired for regular
users.

Thanks Dan Trainor for suggesting the pam_succeed_if rule!
Merge pull request #32 from Miciah/use-pam_succeed_if-before-pam_namespace

Use pam_succeed_if with pam_namespace