nfd-status: Define format and implement --xml option

The ether URI format "ether://01:00:5e:00:17:aa" violates
the URI specification, so it has been changed to
ether://[01:00:5e:00:17:aa] in this commit.

refs: #1438

Change-Id: I1218374b75f919a5e1ab158bbab2e217e64aced3
diff --git a/tests/daemon/face/ethernet.cpp b/tests/daemon/face/ethernet.cpp
index 270abb0..936406b 100644
--- a/tests/daemon/face/ethernet.cpp
+++ b/tests/daemon/face/ethernet.cpp
@@ -118,7 +118,7 @@
   BOOST_CHECK(!face->isOnDemand());
   BOOST_CHECK_EQUAL(face->isLocal(), false);
   BOOST_CHECK_EQUAL(face->getRemoteUri().toString(),
-                    "ether://" + ethernet::getDefaultMulticastAddress().toString());
+                    "ether://[" + ethernet::getDefaultMulticastAddress().toString()+"]");
   BOOST_CHECK_EQUAL(face->getLocalUri().toString(),
                     "dev://" + m_interfaces.front()->name);