CA-141868: Boot options are deleted by New VM Wizard if Installation Media page skipped - Fixed

- Show the page and grey out the irrelevant options (i.e. the installation media if the template has no CD drive).
- Only disable the Installation media step if the template has no installation media and we don't show the boot options (because is HVM).

Signed-off-by: Mihaela Stoica <mihaela.stoica@citrix.com>
Merge pull request #164 from MihaelaStoica/CA-141868

CA-141868: Boot options are deleted by New VM Wizard if Installation Media page skipped - Fixed