Cleanup paths in pdns-recursor.init.d

prefix was unused, the others had a trailing slash, leading to process
command lines like "/usr/sbin//pdns_recursor".
Add exit codes to pdns-recursor init script

Fixes #676.
Update gpgsql queries

fixes #927
silence dead code warning in version.cc
improve += options
change zone backup during tests to zone restore
remove unused files
sdig flags
answer direct NSEC queries without DO bit
Merge pull request #932 from cyclops1982/927

Update gpgsql queries
Merge pull request #931 from rubenk/master

Fix a typo in error message
Merge pull request #933 from mind04/denitify

a little bit of everything
make domainmetadata queries case insensitive
Merge pull request #936 from mind04/903

make domainmetadata queries case insensitive #903
add constraints for name to pg schema
Fix typo in option description
Merge pull request #937 from rubenk/typo

Fix typo in option description
Remove duplicate argument
Merge pull request #942 from rubenk/disable-axfr

Remove duplicate argument
add responsestats infra, not actually reporting yet