Separate Kaminari theme

Prevents ActiveAdmin's pagination from being overriden by any
customizations made to the Kaminari views in a Rails app that uses
ActiveAdmin. Fixes gregbell/active_admin#1126.
Merge branch 'master' into kaminari-theme

Conflicts:
	lib/active_admin/views/components/paginated_collection.rb
Rename Kaminari theme to active_admin
Merge pull request #2048 from jbhannah/kaminari-theme

Separate Kaminari theme