preseve original order of package list used for ICICLE generation

Sorting the default format package list destroys the 1:1 match between it
and any optional extra list, at least for RPM based operating systems.
This also has the unintended side effect of producing a blank <extra> tag for
the final package in the list.
As the sorting is purely cosmetic, and can easily be done on the receiving end
for clients that desire it, just remove it here to address both issues.
Allow libvirt networks with more than one ip block

This can happen with an IPV6 address assigned to a
network, so just make sure to filter out the ones
that have no IP block at all, or that have no IPv4
family (we don't support IPv6 presently).

Signed-off-by: Chris Lalancette <clalancette@gmail.com>