Use Drupal core list of countries and country codes

Better patch, uses public Drupal function country_get_list() rather than internal Drupal function _country_get_predefined_list().

Sigh, that was the same patch. Here's the new one, I hope.

Honest, I really do know how to roll a patch. Don't know what's gotten into me today. Here's what I believe is the correct patch.

The core _country_get_predefined_list() / country_get_list() maintains a static copy of the array with upper class country code keys. Because the Location module uses lower case country code keys, this static copy cannot be used directly. Instead, the upper case keys need to be converted to lower case keys within location_get_iso3166_list() before being returned. My patch did this conversion once then statically cached the converted array with lower case keys - this is in addition to and separate from the static caching done by _country_get_predefined_list() because the array is different. If you don't do the static part in the patch, then the array keys need to be re-converted to lower case and the entire array needs to be reconstructed each time location_get_iso3166_list() is called on a page.

@stevepurkiss: So to summarize, Location is using the wrong 2-character code for the United Kingdom. The ISO 3166 standard says it should be GB (or 'gb' for Location), but Location is using 'uk' instead. When the patch went in that switched to using the Drupal function for the country codes, the Drupal function returned the proper 'gb' instead of the expected 'uk', breaking Location.

I think in addition to #8, there needs to be a renaming of database/zipcodes.uk.mysql (with a corresponding change in the content of that file) and a hook_update() to modify any of the zipcode information already installed in the database. These changes ought to be done anyway - perhaps this should be split off into a new issue?

@stevepurkiss: I rolled a patch for Drupal core about a week ago: #1068840: core/includes/standard.inc contains inaccurate country data. It corrects iso.inc by adding missing countries / deleting an obsolete country / renaming some countries and in general bringing iso.inc into conformance with ISO 3166. I wouldn't mind a review :-)

Ascension Island is part of 'Saint Helena, Ascension and Tristan da Cunha' 654, SH, SHN

I agree BL and MF need to be added to Location, likewise CS needs to be removed in favor of RS and ME, and SW is the wrong code, needs to be SE. There may be a few more that Location is missing if you compare to the updated list from the above patch.