Do not override Mongoid::Criteria#page defined by scope

so we don't have to worry about runtime persistence. closes #326

lib/kaminari/hooks.rb

@@ -18,7 +18,6 @@ module Kaminari
       begin; require 'mongoid'; rescue LoadError; end
       if defined? ::Mongoid
         require 'kaminari/models/mongoid_extension'
-        ::Mongoid::Criteria.send :include, Kaminari::MongoidExtension::Criteria
         ::Mongoid::Document.send :include, Kaminari::MongoidExtension::Document
       end
 

lib/kaminari/models/mongoid_extension.rb

@@ -2,18 +2,6 @@ require 'kaminari/models/mongoid_criteria_methods'
 
 module Kaminari
   module MongoidExtension
-    module Criteria
-      extend ActiveSupport::Concern
-
-      included do
-        class_eval <<-RUBY, __FILE__, __LINE__ + 1
-          def #{Kaminari.config.page_method_name}(*args)
-            super(*args).criteria.merge(self)
-          end
-        RUBY
-      end
-    end
-
     module Document
       extend ActiveSupport::Concern
       include Kaminari::ConfigurationMethods

spec/models/mongoid/mongoid_spec.rb

@@ -120,6 +120,23 @@ if defined? Mongoid
         subject { User.page(2).where(:salary => 1) }
         it_should_behave_like 'complete valid pagination'
       end
+
+      context "with database:", :if => Mongoid::VERSION >= '3' do
+        before :all do
+          15.times { User.with(database: "default_db").create!(:salary => 1) }
+          10.times { User.with(database: "other_db").create!(:salary => 1) }
+        end
+
+        context "default_db" do
+          subject { User.with(database: "default_db").order_by(:artist.asc).page(1) }
+          its(:total_count) { should == 15 }
+        end
+
+        context "other_db" do
+          subject { User.with(database: "other_db").order_by(:artist.asc).page(1) }
+          its(:total_count) { should == 10 }
+        end
+      end
     end
 
     describe '#per' do