* Make the error variable always named err.
Sometimes the error variable was named 'err' sometimes 'e'. Sometimes
'e' refered to an EDNS or string and not an error type.
* Use t.Errorf instead of t.Logf & t.Fail.
Add function that dedups a list of RRs. Work on strings, which
adds garbage, but seems to be the least intrusive and takes the
last amount of memory.
Some fmt changes snook in as well.