Improve select helpers by allowing a selected value of false.  This is useful when using a select helper with a boolean attribute, and the attribute is false. (e.g. f.select :allow_comments)

Specify the template to use in config/database.yml, e.g.

  test:
    adapter: postgresql
    template: template_postgis

If no template is specified, postgresql defaults to template1

This tag is similar in nature to submit_tag, but allows more control.
It also doesn't submit if submit type isn't used, allowing JavaScript to
control the flow where required.

For more information: http://www.whatwg.org/specs/web-apps/current-work/multipage/the-button-element.html#the-button-element

merge_with_conditions is not necessary because the conditions will already be in the scope_for_create hash in the scope

Construct an actual ActiveRecord::Relation object for the association scope, rather than a hash which is passed to apply_finder_options. This allows more flexibility in how the scope is created, for example because scope.where(a, b) and scope.where(a).where(b) mean different things.