Re: [Libguestfs] [PATCH] v2v: Support <listen type='socket'> and <listen type='none'> (RHBZ#1378022).

Since libvirt 2.0.0, these two new <listen/> types have been supported: https://libvirt.org/formatdomain.html#elementsGraphics This change just copies that configuration over from the source to the destination if the destination is also libvirt. Since we previously used 'LNone' to mean "no parseable <listen/> element" I also had to change previous uses of 'LNone' to 'LNoListen', so we can use 'LNone' to mean "<listen type='none'>". Thanks: Ming Xie. ---