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.
i added a test for ```localhost```. 
for hosts with no dot the detected locale will be false and therefor skipped as it wont pass the following if clauses.