v2v: Add a support matrix to the manual page.

This explains what does and doesn't work.
p2v: kickstart: Name the ISO 'virt-p2v'.
p2v: kickstart: Add firewalld to the ISO to allow firewall to be enabled.
p2v: kickstart: Remove 'install' line.

'install' is the default operation, it doesn't have to be specified.
p2v: kickstart: Add rpm to list of packages.

Avoids RHBZ#1089566.