fixing association conditions when MetaWhere is installed (thanks acmetech) - closes #261

Gemfile

@@ -5,6 +5,7 @@ when nil, "active_record"
   gem "sqlite3-ruby", :require => "sqlite3"
   gem "activerecord", :require => "active_record"
   gem "with_model"
+  gem "meta_where"
 when "data_mapper"
   gem "dm-core", "~> 1.0.2"
   gem "dm-sqlite-adapter", "~> 1.0.2"

lib/cancan/model_adapters/active_record_adapter.rb

@@ -36,7 +36,7 @@ module CanCan
         conditions.inject({}) do |result_hash, (name, value)|
           if value.kind_of? Hash
             association_class = model_class.reflect_on_association(name).class_name.constantize
-            name = model_class.reflect_on_association(name).table_name
+            name = model_class.reflect_on_association(name).table_name.to_sym
             value = tableized_conditions(value, association_class)
           end
           result_hash[name] = value