added topleveldomain guesser

added a topleveldomain guesser to map tlds to a locale.
f.e:
domain.ch will map to locale de_CH

this is usefull for sites with more than one tld to provide a default locale per tld.

mappings can be influenced via config.
switzerland being a multilingual country, this example is probably for when your guesser usually will not work... in ch or belgium, people will need to use something else/more.