[api] Ensure parameters are parsed correctly in VariantsController#create
Change out live() usage (removed in jQuery 1.9)

Fixes #2629
Various small admin styles fixes
Error out when loading sample shipping methods if zones don't exist
Fixes promo Add to cart event name

Also takes the opportunity to reorganize event locales under en.yml,
fixes #2562

Fixes #2599
Fixes backend New Product button for edit page

Backend products edit page has too much content already. While we could
just add:

  <div id="new_product" data-hook></div>

to make the form load on the same page imo it's less confusing to just
open the form for a new product in a new page.

fixes #2531

Fixes #2600
Change meta_description on spree_products from string to text

Fixes #2611
Adjust admin product tab selected

removing taxon from the list of controllers which make it selected

Fixes #2579
Refactor product duplication.

Fixes #2641
Use huoxito's suggested fix to fix CheckoutController spec

https://github.com/spree/spree/commit/7825e6dd24fea5810ceaf382736246a81460cfc7#commitcomment-2705000

Fixes #2601
orders api now returns its variants product id #2561 #2565

Fixes #2587
Added CouponApplicator class

Fixes #2548

This is a combination of four commits + this one:

* Use CouponApplicator in API's CheckoutsController
* Fix spec failures
* CheckoutsController spec for apply a coupon to an order
* Removed unnecessary include
[backend] Fix issue where option types were not being correctly set in Admin::ProductsController

Fixes #2639
Display useful message when no payment methods, shipments (for orders) or shipping methods can be found

Fixes #2636
[backend] Correct event_name checks in promotion_adjustments_spec
[api] Remove duplicate tests in OptionTypesController spec
Move money spec to core
Refactor Spree::Money's with_currency and no_cents option settings
Insert non-breaking space in Money objects where currency symbol is afterwards to prevent issues as seen in #2634

This commit introduces the to_html helper for Spree::Money objects

Fixes #2634
Add explanations of components to README.md

Not entirely sure about the backend/frontend distinction since it just happened, so hopefully I got this right.

Fixes #2653