Fix for changed attr_reader in AR 4.0.0.rc1
depend on Rails 4 rc1
remove deprecation notices about connection on instance instead of class
fix for distinct count
remove refs to IdentityMap since it no longer exists
counter cache tests pass without CPK modifications
do not load counter cache patch since it was removed
Merge pull request #154 from codeodor/ar_4.0.x

Updated to work with Rails 4 release candidate 1