Fix DuplicateAlias error when table has more than reference to a second table
Fix issue where relation.dup.arel_table.name can be empty string when app first starts
If sideloaded table is empty should return [] instead of null (matches activemodel serialization behaviour which frameworks like ember expect)
Use json_agg if available
Change sql computed properties on serializers to be instance methods, means current_user alias can be used
Refactor code to inline json function calls instead of wrapping in arel nodes
Add note to readme about potential for serialized dates being invalid when parsed by client
Add tests for nested filtering support issue #21 yet to be fixed