p2v: Ensure the current version of virt-p2v is always displayed.

This will help with debugging customer problems.
p2v: Temporarily remove Configure Network button.

We will ship 1.28 without the capability of configuring the network
(ie. DHCP will always be used).
p2v: Remove p2v-iso directory.

As part of reworking the scripts that are used to build the P2V ISO,
first remove the separate p2v-iso directory.  Similar scripts and
documentation will be introduced back into the p2v/ directory in
following commits.
p2v: Add scripts to make disk or kickstart-based P2V ISO.

Two scripts are added, replacing the make targets from the
previous commit:

virt-p2v-make-disk: Builds a virt-p2v disk or USB key using
virt-builder.

virt-p2v-make-kickstart: Builds a kickstart file (only) which can be
fed to livecd-creator or similar tools on Red Hat-derived distros.

Kickstart generation is slightly different: Instead of requiring the
downstream 'libguestfs-pvhelper' package, the kickstart now embeds the
virt-p2v binary(!) making it self-contained and downstream packaging
simpler.

In addition there are documentation changes.
Version 1.27.39.