Merge pull request #203 from linrock/fix-options

Fix adapters from JSON definitions being ignored.
Convert options to Symbol when loading the JSON.

Alternative solution to GH-203.
.SA host should be whois.nic.net.sa (GH-29)
Remove support for Ruby-based definitions
Add arin adapter to handle ReferralServer directives (fixes #37).
Add specs and fixtures for the arin adapter.