Update for changes to ActiveRecord::FinderMethods#exists?
Update PostgreSQLAdapter#last_inasert_id for railsx 4.1.0
Update JoinDependency#instantiate for rails 4.1.0
Update Associations::Preloader::Association for rails 4.1.0
Fix breakage from 74daa9a6

We still need to look for top level equalities as well as ones
inside an And in case there is only a single key component.
Fix more breakage from 74daa9a6

Some local variables were removed which we need.
Merge pull request #202 from tomhughes/ar_4.1.x

Various fixes for 4.1.x support