netcf: move from meta-virtualization to meta-networking

netcf was orginally introduced in meta-virtualization, since it provides
functionality required by libvirt, but it is otherwise not bound to
virtualization.

So we can move it to meta-networking, and in the process uprev to the
the latest 0.2.3 functinality.

Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Joe MacDonald <joe@deserted.net>