[Enhancement] add PROD variable to RHEL makefiles

- Added $(PROD) to RHEL 6 & 7 Makefiles to match Fedora Makefile as well as make it easier to template
[Enhancement] add PROD variable to Openstack and RHEVM3 Makefiles
[RHEL7] Update RHEL6 to 7 ext4 to xfs

Simple system permissions update for RHEL6 to 7
Change Openswan to Libreswan
Merge pull request #290 from neo-aeon/Openswan_to_Libreswan

[RHEL7] Change Openswan to Libreswan
X11, switch inittab to default.target
Audit auid switch 500 to 1000
Merge pull request #291 from neo-aeon/inittab_to_set-default

[RHEL 7] X11, switch inittab to default.target
Merge pull request #292 from neo-aeon/audit_uid_1000

[RHEL 7] Audit auid switch 500 to 1000
Merge pull request #284 from redhatrises/makefile_updates

Makefile updates - add $(PROD) variable