zone2lmdb and lmdb-backend regression tests
first baby steps to dnssec in lmdb-backend
import dnssec records in lmdb database
get NSECx direct from backend and use it for lmdb-backend
get RRSIGs direct from backend and use it for lmdb-backend
store lmdb metadata in zone record
fix NSEC in lmdb-backend
unswap ttl and IN in saxfr output
put lmdb-backend dnssec support behind lmdb-experimental-dnssec switch
Merge pull request #1450 from mind04/lmdbsec

lmdb-backend experimental presigned dnssec support, zone2lmdb and regression tests
SSL support for Socket and remotebackend