Add add-on request to $joins

Adds add-on information to the order export output.
Add Add-on Name to exportcolumns

To add add-ons to order export output.
Merge pull request #2842 from Just-m/1.3.x

Add add-ons to order exports
Closed #2844 Namespaced the is_{name}_page() calls to use is_shopp_{name}_page
Fixed #2839 Corrected warning header formatting so theme template copying works
Changed deprecated api call

Use shopp('cart.apply-code') instead of deprecated shopp('cart.promo-code');
Merge pull request #2845 from ben72/patch-2

Changed deprecated api call in cart.php
Added shopp_create_$classhook hook to allow actions on new objects for all object types.
Fixed #2846 Moved  checkout request redirect to only occur with shopping cart requests

In particular, we must make sure this only runs after $_REQUEST['cart'] is present ( ! empty() ) so that we are sure it only occurs if a cart request is present and detected. In 1.2, this occurred in the Cart->request() handler which fired on the shopp_cart_request action hook.

For this fix, we're moving it to after the shopp_cart_request hook so that it is in a similar location to where it processed before, but living in different code (the super-controller in this case).
Fixed #2847 Set sort order for shopp_product_set_addon_options.
Fixed #2835 Corrected smart collection option loading and loop handling

The smart collection loading option changes may cause unintended consequences elsewhere in the system. While core smart collections work, testing is needed to verify integrity of other collection loading and especially smart collection option handling from the Theme API.
Merge branch '1.3.x' of code.shopp.net:core/shopp into 1.3.x
Fixed #2836 Corrected quality and sharpen min/max range handling in storefront.image
Typo
Merge pull request #2848 from Just-m/1.3.x

Typo
Corrected inline documentation
Closed #2814 Added get_terms argument pass thru support to storefront.has-categories
Fixed #2841 Corrected the filter hook references for description formatting handlers
Typo in code

Forgotten ; in two places.
Fixed  #2823

Using reverse logic on tax-inclusive