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.
mm no, i forgot that the toploveldomain is set as locale by default and then its checked if there is some additional mapping.
then its checked if its allowed.

f.e. domain.de means locale=de, even if its not set in the configuration.
if de however is not allowed by configuration it will not be set as locale.
so we have to validate here.

the map is mainly for ambiguious topleveldomains and tlds that dont match their locale.