Only the test initialization and the singleton accessor functions are
implemented for now (and tests for those).

No need to create an opened socket and close it right away.

The dns_service is not tested, so the tests are not added. It is simple
anyway.

reviewed on jabber

details.  This should solve failure of some AXFR tests using SQLite3 on
some systems.

redundant 'pass'

to avoid duplicates.

counted twice.

section.  also extended tests to check the length the actual wire format
data for some specific cases.

account the DNS header size.  also added consideration for very large RRs
that would not even fit a single DNS message.

(I thought I did it in the IXFR tasks, but maybe I forgot to commit/push
that part)

It is already the 29th in some parts of the world.

See ticket #1430 for more details. (Ticket pending tests before closing.)

Put correct git revision hash.

Remove review comment.

Remove no trac number comment.

Rejustify another entry while here.