Make auto_capture? a per payment configuration

Fixes #4302
Do not use orders_per_page to determine amount of zones returned in Admin::ZonesController

Fixes #4305
Duplicate variants when duplicating products

Fixes #4029
Fixes #4264
Use a test email address in checkout_spec so that I'm not subscribed to random mailing lists
Ensure products get assigned a 'proper' permalink when duplicating

The caveat of this is is that if you clone a deleted product, it'll look something like this:

copy-of-1392174386_apache-baseball-jersey-1

That's easily fixable, though.

Fixes #4180
Correct check for permalink in product duplicator spec
No longer run the actions for a promotion if that promotion is not eligible

Fixes #4270
Add dependent destroy to category mapping table

Fixes #4312
[api] Use a valid order with line items in coupon code application test

This is necessary due to the changes within c623e54df876f45cbf16729034ff9c4297436bd3
order concurrency for 2-1-stable spree

* separate PR for 2-1-stable due for https://github.com/spree/spree/pull/4286

Fixes #4334
Return true/false with Promotion#activate

This way, you can tell if the promotion was really activated or not
Show the coupon_code_not_eligible if Promotion#activate returns false in CouponApplicator