Backport of software raid to roxy (part 1)

Rewritten data attributes to accept multi values

Now you can assign multiple values seperated by `;` to
these data attributes:

* data-showit
* data-hideit
* data-enabler
* data-disabler

(cherry picked from commit ced63755afa9bc4f1af0b50db1c778563667e78e)

This is exactly https://github.com/crowbar/barclamp-crowbar/pull/922 -- there was no conflict during cherry-picking.