[Enhancement] [RHEL/6] Add initial USGCB profile kickstart suppport for Red Hat Enterprise Linux 6 Workstation

One of the steps for the corresponding SCAP content to become official is the requirement to provide kickstart support (ability when particular kickstart is applied the system once installed would comply with particular security profile). See issue: https://github.com/OpenSCAP/scap-security-guide/issues/306 for further details.

We will start with adding initial kickstart support for USGCB profile for Red Hat Enterprise Linux 6 Workstation product.

The attached kickstart doesn't install a fully-compliant USGCB profile Red Hat Enterprise Linux 6 Workstation instance yet (~74% of the rules pass past installation). But this is caused:
* either by the particular remediation script to modify runtime state,
* or the remediation script in question to fail / return with error (these will require further investigation within separated ticket, since those rules would need separate fixes).

Kickstart output:
Creates "~74%" compliant USGCB profile Red Hat Enterprise Linux 6 Workstation instance. Bootloader password is 'password' & root / privileged system user password is 'workstation'.

Testing:
Has been tested via virt-manager & works fine.

Own testing notes:
The kickstart assumes there's Red Hat Enterprise Linux 6 Workstation Update 6 ISO image mounted at / under:
&nbsp; &nbsp;  http://192.168.122.1/image
location.

Once this is done, the system can be installed e.g. via virt-manager by specifying particular system path to the kickstart file, e.g selecting ```Network Install (HTTP, FTP, or NFS)``` option for virt-manager, and using
```URL``` of the value of http://192.168.122.1/image & ```Kickstart URL``` (in the URL Options menu) path to kickstart file e.g. http://192.168.122.1/usgcb-workstation-ks.cfg (under assumption that kickstart is placed in system's /var/www/html directory [Be sure you have firewall httpd exception enabled if using this]).

Please review.

Thanks, Jan.