dependent_select.rb is not needed. Just included all code into dependent-select.rb.
Best would be if the complete lib is renamed to dependent_select instead of dependent-select.
Updating support to formtastic 2.0 and above
Trigger the change on the parent property to filter the list on pageload.
Undid the reversing of output.
Select value from object.
html-escaping introduced into option template via Mustache
Also added the ruby Mustache for templating in Ruby code