[AndyB] Country access check 1.6

Blocks access to Contact us, Log in and Register pages from specified countries.
(Example of options page)

(Example of error message)

(Example of Country access check page)

Features:

• Uses ipapi.co for accurate country locations.
• All phrases start with countryaccesscheck_ for your convenience.

Setup:
Enter country codes into options page.
View countries registration check page:
To view a list of blocked countries, add 'countryaccesscheck' to your forum URL. Must be an admin to view this page.
Database changes:
A table called andy_country_access_check is created in your database.