refactoring and adding SCL passenger support

One, policy was refactored with respect of recent changes in RHEL 6.4+ base
policy (passenger_t and httpd_t domains).

Two, we added SCL passenger support. There are two steps:

a) In foreman.fc we added file contexts in /opt/rh/ruby193/...

b) During installation, in the foreman-selinux-relabel, we relabel this
directory recursively.

Please test with SCL and without SCL mod_passenger and report AVC logs here.