Properly implement interface.create and interface.destroy.
Properly implement interface.create and interface.destroy.

They were marked as taking a variable number of inputs,
but they were not coded that way.  Fix them up to take
the right number of arguments.

Signed-off-by: Chris Lalancette <60b62644009db6b194cc0445b64e9b27bb26433a@redhat.com>

libvirt/ruby-libvirt,libvirt/ruby-libvirt,libvirt/ruby-libvirt