Current API provides a "query plan" for each zone, which is
basically a set of steps it needs to takes a query to be resolved.
The plan is divided into several stages that reflect answer section
processing. Now this query plan can be altered via configurable modules,
first module is a 'synth_record' that makes synthetic forward/reverse
records if the query isn't satisfied from the zone contents.

DDNS tests for new test suite

Include config.h

The config.h is now implicitly included using -include option of the
compiler. After this change, config.h need not be placed at the first
position in all source files.

problems:
* code insertion point makes it hard to provide DoE proof here
* query for given name but wrong type yields NXDOMAIN while it should
* be NODATA
* both rules need to specified in the config, inconvenient
* substring matching is tricky, prefix would be simpler I think

refs #166

Conflicts:
	src/knot/server/xfr-handler.c

Conf Optimization

Auto Retransfer

refs #220

*14.102.145.in-addr.arpa. is valid dname (no wildcard!) but evident typo

refs #220

 - random test used for chain fix testing
 - manual test, some of the cases copied from the old tests, but not all.

Signing after UPDATE fixed

Fixed changeset signing after UPDATE.

Was ignoring RRSIGs related to a RRSet that was completely removed. This was a relict of old code when RRSIGs were connected to their RRSets.

Also simplified the function (and function `sign_rr_should_be_signed()`) and did some minor refactoring and polishing. Please try to check if function `sign_changeset_wrap()` is equivalent to its previous state.

Revert NSEC chain fixes due to excessive complexity of the code.

- A lot of bugs were uncovered with new tests and fixes got out of hand - the code was no longer readable (not that it was readable before)
- Totally unfeasible to fix before new zone API is done. I've fixed the code, but the result was too complex, unmaintable.

- no proofs yet
- no forward records

Zscanner Interface

Was ignoring RRSIGs related to a RRSet that was completely removed.
This was a relict of old code when RRSIGs were connected to their
RRSets.

Also simplified the function
(and function sign_rr_should_be_signed()) and did some minor
refactoring and polishing.

Zscanner Building