dns/pear-Net_DNS2: Update to 1.4.4

Changelog:

• bugfix when returning an empty bitmap-type in BitMap.php
• added the BIND 9 private record RR (TYPE65534)
• added DNSSEC algorithms 13-16 (ECDSAP256SHA256, ECDSAP384SHA384, ED25519, and ED448).
• added SSHFP algoritm ED25519.
• modified Net_DNS2::sendPacket() to use current()/next() rather than the deprecated each() (deprecated in 7.2).

While here, switch to DISTVERSION

Approved by: mentors (implicit)