[Libguestfs] [PATCH API PROPOSAL 0/2] inspection: Add network interfaces to inspection data.

As part of the fix for: https://bugzilla.redhat.com/show_bug.cgi?id=1626503 I'm proposing to add two new APIs to fetch information about the list of network interfaces of an existing guest. These two patches outline the proposed API but with no implementation or tests. However they can be applied and compiled. Please see the second patch for the proposed API. I have a mostly working implementation for Red Hat-style ifcfg-* files, and both Debian /etc/network/interfaces and Windows registry look do-able using the same architecture. Rich.