[Enhancement] Port single_user_auth to RHEL7 and Fedora

- Update RHEL7 and Fedora XCCDF for require_singleuser_auth
- Update require_singleuser_auth OVAL for RHEL7 and Fedora
Fix typos in OVAL
[bugfix] update manpage for RHEL7 to support RHEL7 content

- Update man page for RHEL7
- Add rht-cpp and common profiles to manpage
- Add draft USGBC
- Fixes #283
Update RHEL7 manpage to use shipping profiles
Update OCIL clause for single-user-auth

- Update OCIL clause for RHEL7 and Fedora
Merge pull request #261 from redhatrises/single_user_auth

[Enhancement] Port single_user_auth to RHEL7 and Fedora
Remove CPE variable from the example from the RHEL7 manpage
Merge pull request #287 from redhatrises/man_page_updates

[bugfix] update manpage for RHEL7 to support RHEL7 content