Add TestDynamicUpdateParsing test
Merge branch 'master' of github.com:miekg/dns
Merge pull request #113 from asergeyev/master

No timeouts in tests
Parse dynamic update RR in presentation format

Don't panic when encountering dynamic update RRs in zonefiles.
There are some other failure cases when parsing, those will be
fixed in subsequent commits.

Closes #110
And actually fix the parsing
fmt
Fix datarace in Start/Shutdown

Add mutex and guard a 'started' boolean as well as the stopUDP
and tcpTCP channels so that 'go test -race' does not trigger.

Closes #111, closes #114