Change country array to sort on name, not key

Every single time I use PyroCMS on a client installation, I have to go and edit the country field directly.

For an average user, having a list of countries means they are in alphabetical order based on name; I know of literally 0 people who can sort based on ISO country code in their head. It's a source of confusion.

In my usual edits, I actually change this to have the user's country at the top of the list, but seeing as this is a pull request I simply ordered everything accordingly.

Also, this could probably also go into the 2.2 branch, as well.