Avoid errors caused by missing active record files
ActiveRecord version >= 4.2.0 need version of pg gem >= 0.15
For ActiveRecord 4.2 change class ActiveRecord::PredicateBuilder::ArrayHandler instead of changing the class ActiveRecord::PredicateBuilder.
Fix postgres_ext for rails 4.1
Merge pull request #146 from azomazo/fix-support-rails-4.2

Changing the way of support for arrays in rails 4.2
Merge pull request #145 from MatthewRDodds/master

Avoid errors caused by missing active record files
Use delegate for relation_delegate_class
Merge pull request #147 from eidge/master

Fix postgres_ext for rails 4.1