Add Net/DNS2 PEAR library

include/pear/Net/DNS2.php

include/pear/Net/DNS2/BitMap.php

include/pear/Net/DNS2/Cache.php

include/pear/Net/DNS2/Cache/File.php

include/pear/Net/DNS2/Cache/Shm.php

include/pear/Net/DNS2/Exception.php

include/pear/Net/DNS2/Header.php

include/pear/Net/DNS2/Lookups.php

include/pear/Net/DNS2/Packet.php

include/pear/Net/DNS2/Packet/Request.php

include/pear/Net/DNS2/Packet/Response.php

include/pear/Net/DNS2/PrivateKey.php

include/pear/Net/DNS2/Question.php

include/pear/Net/DNS2/RR.php

include/pear/Net/DNS2/RR/A.php

include/pear/Net/DNS2/RR/AAAA.php

include/pear/Net/DNS2/RR/AFSDB.php

include/pear/Net/DNS2/RR/ANY.php

include/pear/Net/DNS2/RR/APL.php

include/pear/Net/DNS2/RR/ATMA.php