removes bdb&tc registry; adds dbm registry

This removes the existing registries, ruby-bdb (Berkeley DB) and
tokyocabinet, instead it creates a new registry based on ruby
DBM.
Ruby-bdb has long since been abandoned in favor for rubys DBM
and tokyocabinet also has been ceased development since
2011 (for kyotocabinet).
[registry] removed temp logging
remove old/compat code no longer supported
log fatal/error messages to stderr, but check if daemonized first!
[registry] standalone import/export/migrate script