refactor ActiveAdmin.flash
make ActiveAdmin.flash’s closable
close after attr for js flash messages
Allow CSV export without column name
Document column_names paramters for csv
Simplify code
remove admin_user locale keys
some styling for input[type=button] as for input[type=submit]
some styling for button as for input[type=submit]
Merge pull request #3416 from timoschilling/i18n_remove_admin_user

remove admin_user locale keys
Bump formastic to ~> 3.0
test against Rails 4.1.6
cleanup
Merge pull request #3431 from timoschilling/code_simplification

cleanup
Fixed markup 

Fixed markup for configuration of on_unauthorized_access
fix misspelling in CHANGELOG
simplify AssetRegistration
cleanup ActiveAdmin::Application#namespace
Merge pull request #3437 from timoschilling/simplify_asset_registration

simplify AssetRegistration
Merge pull request #3433 from macarthy/patch-2

Fixed markup