Bug 1981: NumberFormatException in ArpResponderService while programming Static ARP entries

The function ActionUtils.nxLoadArpShaAction() can now take a BitInteger or MacAddress.

Change-Id: Ia53a1e32d33b69f2ec0453d5c816d5f8c404814d
Signed-off-by: Flavio Fernandes <ffernand@redhat.com>
Signed-off-by: Madhu Venugopal <mavenugo@gmail.com>