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
sortable has-many
Merge pull request #2656 from igorbernstein/has_many-sortable

sortable has_many
Merge pull request #2048 from jbhannah/kaminari-theme

Separate Kaminari theme
tabs -> spaces
fix z-index priority for parent menu items

fixes #2702
better CSS for long menu items with children
Fix the margin on nested has_many sortables
Remove duplicated CSS rule
Merge pull request #2707 from shekibobo/fix-sortable-margin

Fix the margin on nested has_many sortables
Merge pull request #2705 from seanlinsley/css/2704-long-menu-items

[2704] better CSS for long menu items with children
Update rspec to expect syntax, plus == to eq