Cleanup regression-tests.api test suite

Fix PEP8 stuff.
Also fix a not-actually-testing-the-output case.
API: Fix decoding of symbols

=2F needs to be a slash, but we thought it was a #.
Merge pull request #1420 from zeha/api-testsuite-cleanup

Cleanup regression-tests.api test suite
API: Don't require nameservers list for Slave zones

When creating a Slave zone, it usually doesn't make a lot of sense
to create NS records, as they'll be overwritten by the slaving mechanism
anyway.
This allows not passing 'nameservers' in at all.

Fixes PowerDNS/pdnsapi#2.
Merge pull request #1423 from zeha/api-slave-no-nameservers

API: Don't require nameservers list for Slave zones
API: create slave zones completely empty

We should not insert a SOA record, as this would cause serving
of NXDOMAIN until the domain has been slaved.

Fixes #1425.
Merge pull request #1428 from zeha/api-slave-no-soa

API: create slave zones completely empty
remove confusing duplicate option experimental-json-server for pdns_recursor. Right now it is the only webserver we have, use experimental-webserver
Drop experimental-json-interface from tests and doc
Merge pull request #1430 from zeha/e-j-i

Drop experimental-json-interface from tests and doc
stay away from getaddrinfo unless we really can't help it for ascii ipv6 conversions to binary
return NOTIMP for direct RRSIG request
re-enable bind hybrid support
Revert "There are certain situations in which getAuth() may want to be overridden by a
backend for performance reasons. The attached patch converts getAuth() into a
virtual backend function. The default is for no change in functionality. In my
tests this leads to very significant performance improvements under certain
situations"

This reverts commit 8208210a367e200f5f16463e83c208a28ddc24c0.

Conflicts:
	pdns/packethandler.cc
don't use 'new' getAuth() in webserver