Merged pull request #343 from rahearn/mongoid-scope.

Adds ability to use Scope query with Mongoid
Augments Mongoid adapter by handling case where attribute is an array
Merged pull request #352 from cardagin/topic/mongoid-adapter-enhancements.

Augments Mongoid adapter by handling case where attribute is an array
Use dkubb's suggestion for evaluating conditions against a Resource.
Fix pending spec for DataMapper adapter.
Return empty set early if no can rules are present.

Thanks dkubb!
Merge pull request #355 from emmanuel/issue/245.

DataMapper adapter improvements
Fixes bug in mongoid_adapter with empty conditions hash

* adds mongoid query that matches every record when
rule.conditions.empty? is true
Processes can rules only if no empty conditions rules are present

1) remove all empty conditions hashes from the rules, they are included
 in the records through `@model_class.all`
2) only process can rules if the new and old rules lists are the same
  length (meaning there were no empty conditions hashes)
3) always process cannot rules
ensure Mongoid::Document is defined before loading Mongoid adapter - closes #359
allow :through option to work with private controller methods - closes #360
adding current_ability to helper methods - closes #361
Merge pull request #363 from rahearn/mongoid-conditions-empty

Fixes bug in mongoid_adapter with empty conditions hash
pass action and subject through AccessDenied exception when :through isn't found - closes #366
releasing 1.6.5
allow :find_by option to be full find method name - closes #335
delegating ControllerResource find to model adapter, uses 'get' for DataMapper - closes #373
Make CanCan Default Message a translatable text. Default to the one you had.
Adding tests for i18n translation for default messages
Change the i18n default name to :"unauthorized.default"