added ability to use sort order in CSV
fix title of pages with active_admin_logged_out layout (fix #3428)
use same item dsl for actions and actions with dropdown (fix #2625)
join IndexAsTable default actions
extend documentation for new index actions style
Documented the `:optional` option for belongs_to

I found the `:optional` option very useful for a project to expose nested resources in the global menu ; here's a short proposal to expose it in the documentation.

Thanks for all the good work in activeadmin, you rock!
remove i18n key `active_admin.update_model`

This key is not used by active admin, see #3172
remove i18n key `active_admin.create_model`
don't configure authentication_method if devise isn't used (fix #3467)
Name action items; allow removing them by name

Ref #760

Name first parameter to action items.
It is still optional in the DSL, but triggers a deprecation warning when not provided.
Merge pull request #3091 from carnesmedia/name-action-items

Name action items; allow removing them by name
suppress and spec deprecation warning in dsl_spec
Refactor FormBuilder#has_many by extracting methods.
Refactor FormBuilder, replacing form_buffers with Arbre components.  See PR #3486 for discussion.
Remove form_buffer from filters form.
Fix active_admin_comments now that active_admin_form_for is a nested Arbre component.
Fix new password form, we can no longer break up active admin form in an ERB template.
Remove duplicate copy of test.
Formtastic + Arbre: will it blend?
Update documentation for forms including Arbre.