add constructor to append two elements to ContentName, as this is going to be a common case
add constructor to append two elements to ContentName, as this is going to be a common case


cawka/ndnx,ebollens/ccnmp,svartika/ccnx,svartika/ccnx,svartika/ccnx,cawka/ndnx,svartika/ccnx,cawka/ndnx,svartika/ccnx,cawka/ndnx,ebollens/ccnmp,ebollens/ccnmp,svartika/ccnx,cawka/ndnx,ebollens/ccnmp,svartika/ccnx