remove kaminari theme

ActiveAdmin use the default Kaminari theme, thats not nessary to have this theme inside of ActiveAdmin we can use it from the gem.
Merge pull request #3653 from activeadmin/remove_kaminari_theme

remove kaminari theme
fix phantomjs/poltergeist

refs #3623
Fallback to use formtastic inputs
change filters input look up

move all filter inputs in his own namespace to support formtastic input_class_finder with fallback to default inputs.

refs #3633
closes #3678, #3696