SimpleXML is included in PHP by default as of PHP 5.1.2. Because Drupal 7 requires PHP 5.2.5 or higher, we no longer have to check for SimpleXML in hook_requirements().

Use extension_loaded() instead of class_exists() in hook_requirements().  Modify URL link for SimpleXML.

Overhaul and reorganize UPS and USPS admin settings pages. Put settings into fieldsets, make settings and layout consistent between the two modules. Add weight markup setting.  Rename markup variables to differentiate between rate markups and weight markups. Add hook_update() to preserve old markup values. Add weight markup functions. Weight markup left disabled in admin, because package_products still has to be modified to understand weight markups.

#698336 by Island Usurper: Port database schema API changes for core modules.
By Andy_Lowe: Make changes to uc_store as suggested by coder_review.

Alpha 6 upload!  Plenty of bugfixes and feature additions, including code updates, more countries, and better international support.