LMDB-based very high performance backend
Merge branch 'lmdb-back' of https://github.com/mzealey/pdns into mzealey-lmdb-back

Conflicts:
	.travis.yml
silence bunch of warning in lmbdbbackend
add missing ' to error message
cleanup gsql-master regression test scripts
remove duplicate code from gsql-master test scripts
fix axfr source for goracle-slave tests
add postgress-slave mode to regression tests
use pdnssec for tsig keys and metadata in tests
add tests new tests to travis.yml
fix feedEnt query
run nodnssec slave tests without the (backend)-dnssec option