Made ipwrapper.py:Route class more robust

Route can now parse routes of the form:
'local 127.0.0.1 dev lo  src 127.0.0.1'

Change-Id: Id2d62ad31bd9d5c7bea28605a0b195c1886f0dab
Signed-off-by: Assaf Muller <amuller@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/21788
Reviewed-by: Antoni Segura Puimedon <asegurap@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>