exclude test should sort the array result and expected array

why? because postgresql won't always return the two expected results in
he expted order so the test failed intermittently.
updated specs for 'select distinct' issues

* new model/table with a json column for postgresql specific testing
* add tests for explicit distinct in a select and for all queries to
  test if tagged_with adds a distinct clause on the query.
    http://github.com/mbleigh/acts-as-taggable-on/issues/357
* add tests for taggable_model_with_json
use a group rather than a distinct when options[:any] is true