Remove array serialization. No longer needed for Rails 4
Remove migration support for hstore and json. Built in to Rails 4
Fix JSON for Rails 4
Fix hstore support to work with Rails 4
Fix array scopes for Rails 4
Fix deprecation warnings with association conditions/orders
Fix last deprecation warnings for Rails 4
Remove obsolete benchmarks
Fix Rails 4 deprecation warnings
Update documentation for Rails 4 version
Update README.md

Fix typo
Rails 4 support
Rails 4 is now master branch