pull in RHS2 kickstart customizations using %include

This patch removes the hardcoded customizations from the RedHatStorage2
kickstart template, which were based on RHS-2.0-20120320.2 but were not
applicable to other releases.

Instead the template includes the necessary custom bits from
kickstarts/ksappend.cfg underneath the distro tree itself, using the
%include directive. That way Beaker's kickstarts will always have the
appropriate customizations without needing to update the templates for
every RHS2 release.

The template now matches RedHatEnterpriseLinux6 apart from the %include
and a few other small differences.

Bug: 903416
Change-Id: Iff82ebefe531ed00aeb4a768d22274028dd3b1d1
Merge "pull in RHS2 kickstart customizations using %include" into develop