Merge remote-tracking branch 'akashkamboj/rails4'

Conflicts:
	lib/active_admin/inputs/filter_boolean_input.rb
	lib/active_admin/resource/naming.rb
Merge remote-tracking branch 'origin/metasearch->ransack'

Conflicts:
	lib/active_admin.rb
	lib/active_admin/comments/comment.rb
	lib/active_admin/sass/helpers.rb