ipwrapper: Get rid of unused methods

In the move to libnl's netlink interface to the kernel networking
information we stopped using several of ipwrapper's methods. This
patch removes those that had no usage whatsoever.

Change-Id: Iba2a8ee4a978c61f7db934e5b08cf2f74923627f
Signed-off-by: Antoni S. Puimedon <asegurap@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/29726
Reviewed-by: Ondřej Svoboda <osvoboda@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>