Ruby library for integrating with the 42Floors MLS

Adds a #sort query method to ActiveRecord that turns whitelisted user-supplied parameters into ORDER BY clauses -- ordering by columns or associations, ascending/descending, with NULLS handling and random ordering -- without exposing you to SQL injection.

Extends Arel and ActiveRecord with SQL operators and functions that aren't available out of the box, including array and JSON predicates, PostgreSQL full-text search (tsvector/tsquery), GIS/geometry predicates, and additional ordering helpers.