Add a JS hook for has_many_remove:after
Trying the latest ransack

Trying the latest ransack to be compatible with the latest squeel.
Uses ransack 1.3

Uses ransack 1.3 to be compatible with the rails 4.1
update rails_template.rb for rails 4.x

remove the "public/index.html" file only if it exist, rails 4.x don't have this file.
update issues tracker search url in CONTRIBUTING
git ignore bin folder (for rails 4 dev usage)
reimplement `ActiveAdmin::ResourceController performing batch_action` spec
implement missing spec in unit/resource_controller_spec
fix test for 1.9.x
cosmetic
implement missing filter form builder spec #1
implement missing filter form builder spec #2
Easier extending default show page

I would like to add few fields to show page, but keep the defaults.

Passing block to `default_main_content` would make it use defaults + block.
Merge pull request #3357 from timoschilling/specs2

add missing filter form builder specs
Merge pull request #3353 from timoschilling/fix_rails_template

update rails_template.rb for rails 4.x
introduce ActiveAdmin.flash
tests for ActiveAdmin.flash
Use a select field for a boolean input
fix site title of namespaces
Use Ransack 1.3 or higher