src/lib/dhcp/iface_mgr.*
    IfaceMgr::isReceiverRunning() - new, public convenience method

src/lib/dhcp/tests/iface_mgr_unittest.cc
    Revamped sendReceive<4/6> tests to test both direct and
    indirect packet reception

    TEST_F(IfaceMgrTest, configureDHCPPacketQueueTest4)
    TEST_F(IfaceMgrTest, configureDHCPPacketQueueTest6) - new tests