and use the holder in the unit tests as well

Half-related change, if available, call mysql_library_end() at the end of the unit test run

Clean up docs/design/cc-protocol.txt

Conflicts:
	doc/design/cc-protocol.txt

it was a leftover from an intermediate attempt.

assuming the compiler optimizes the former (more understandable but
possibly less efficient) to the latter (less understandable but
efficient).

reviewed by jelte via jabber.

Changes some log message descriptions and some
function arguments and some output.

adjusted one unit test case based on the message change.

we previously relied on boost rejecting the padding chracter and throwing
an exception; since Boost 1.53 paddding characters are considered valid
and conerted to all-0 bits, so we now have to do it ourselves.  The detection
logic doesn't rely on the new behavior of Boost, so it should be backward
compatible.

transform_width in Boost 1.53 requires this version, so build will fail
without it.

This is so that we can avoid merging RdataSets every single time which
can be inefficient.

We still only queue (without flushing) upto the point where a different
owner name is encountered. This is to limit the size of NodeRRsets used.

This does have the side-effect of no longer sorting the printed list in the logger manager.
(if we do need that, we should add a MessageInitializer::sortDuplicates i think)

It is now a thin wrapper around the ZoneDataUpdater.

The ZoneDataLoader can still be simplified to remove the vectors
in it (as the RdataSet now merges for us). This will be done
in a future commit.

* In some tests, the RdataSet list sequence changed (as there's no
  order enforced for this data). Tests were adjusted for it.
* Some test data was adjusted to add missing NS records.
* Some tests now pass and don't throw exceptions as duplicate
  records for a type are now accepted.

initialize message loader in PyInit_datasrc.
Updated one of the general lettuce tests to check the symptom (don't know how else to test this tbh)

Make it more up-to-date. Also, provide some info about the want_answer
header and what is being sent over the wire as payload.