Added three letter codes for the countries that were missing them.
Patch from TJ Mather.
Documentation bug: one of the examples used => where the lvalue was
a constant, which isn't allowed, unless you put the () with the
constant to force the right interpretation. Pointed out by TJ Mather
and MYT.
Updated the URL for the appendix in the CIA world factbook. Patch
from TJ Mather.