#48 Top Domains box and from_domain don't regcognise ccTLDs

[Chris Butler]

The Top Domains box and the from_domain.php page do not
recognise ccTLDs such as ".co.uk" or ".com.au".

The attached patch changes the SQL in these pages to
check the length of the final part of the domain name.
If the final part is a two letter ccTLD (instead of a
three-letter gTLD), it will take the last THREE parts
of the domain, instead of the last two.

[Chris Butler]