[libvirt] [PATCH 0/3] IPv6 / multi address / report live config in virInterface

This is the 2nd iteration of this patchset incorporating danpb's suggestions. Along with a couple other minor things, the type attribute is again a required attribute, and netcf support will be omitted in the build unless you have netcf-devel-0.1.3 or greater. Since there is no netcf-devel-0.1.3 yet, I tested this by changing the appropriate strings to 0.1.2. 0.1.3 will be released "soon" (I want to try and get IPv6 address reporting in before lutter cuts another release). I just wanted to get the patches to the list early to get some visual review in case I screwed up anything new ;-) Note that (unless you're building/installing netcf from the head of git) if you try to fake out the version of netcf yourself you'll get runtime errors from virInterfaceGetXMLDesc (iface-dumpxml) due to there being no "type" attribute in the interface xml.