Include ksmeta variables when rendering kernel command line options

It might be useful to have the kickstart metadata variables available when
rendering the pxe kernel command line options. For example, one might want
to use kickstart metadata variables when defining the kernel options.

Signed-off-by: Nathan Ozelim <natoze@linux.vnet.ibm.com>
Merge pull request #713 from alanoe/alanoe/add_ksmeta_to_pxe_kernel_options

Include ksmeta variables when rendering kernel command line options