Added Australian and South African regions and an All Regions option

As mentioned [on Devot-ee.com](http://devot-ee.com/add-ons/support/reegion-select/viewthread/13025), here's the updated add-on. Aside from added the 2 countries' states/territories/provinces, I moved the logic that converted the UK counties array into a named key array out from the fieldtype file, and put it in libraries/regions.php. I was having issues integrating the UK counties into the All Regions dropdown, and preparing the array ahead of time seemed like the best option.

Arbitrarily updated the version number from 2.1 to 2.2 - completely up to you.

I've done some basic testing and everything seems to work fine, both plugin and fieldtype.

Thanks for a great add-on!