Rename *_filter callbacks to *_action callbacks

Deprecate *_filter callbacks in Rails 4.2
https://github.com/rails/rails/commit/6c5f43bab8206747a8591435b2aa0ff7051ad3de

Fixes #5239
Add changelog about filter deprecation.
Fix payment state logic to only result in failed if there are no valid payments.
Fix potential tax calculation issues with charging of unreturned expedited exchanges

* Test that taxes are included
* Make sure to hit all state machine transition events

Conflicts:
	core/lib/tasks/exchanges.rake

Make sure not to ship again on an unreturned expedited exchange

Conflicts:
	core/lib/tasks/exchanges.rake

Fixes #5237
Allow Product.orders

One thing that our store admins need to do often is find the orders that have been made for a given product. This can be easily achieved by adding these `has_many through:` lines. This seems like a capability that other stores might find useful as well.

Fixes #5247