Point documentation to correct source.
add_routes introduced in Spree v2.1.x

See: https://github.com/spree/spree/issues/3757
Engine tweaks.
Add :remark to allowed params.
Ensure Travis test latest 2.1.x.

And remove mail spam.
Fixes untranslated locale keys.

Back-ported from 2-3-stable branch.
Fixes abilities.

Back-ported from 2-3-stable branch.
Add Swedish translation.
Update .gemspec and dev dependencies.
Add Guardfile.
Add full spec coverage for RSpec 2.99.0

Back-ported from 2-3-stable branch.
Throw RecordNotFound when wishlist is not found

Fixes #68
Regression test for issue #68
Fix add to cart
Create pt-BR locale
Add dependent destroy to wishlist's wished_product association to avoid orphaning wished_products if wishlists are destroyed