make NSEC3 opt-out optional
add secure delegation to regression tests and fix NSEC3 for delegations
for some reason the NSEC3 fix was not in the last commit
bind backend getBeforeAndAfterNamesAbsolute fix
add secure delegetion test setup to all backends
Merge branch 'nsec3optout' of ssh://github.com/mind04/powerdns into nsec3optout

Conflicts:
	regression-tests/nsec-wildcard/expected_result.narrow
	regression-tests/nsec-wildcard/expected_result.nsec3
fix merge
Fix nsec3 optout and don't sign  NS records in normal nsec3 mode
Update tests
Change default to NSEC3 opt-out
Merge branch 'master' into nsec3optout
Merge branch 'master' into nsec3optout
Add optout tests to .travis.yml