Add language parameter to offline search

[jaakla]

App can set parameter language=en, language=es etc for both geocode and reverse-geocode requests. For geocode it gives hint, for reverse-geocode sets preferred language. Maybe add language also as paratmeter to NTAddress object.

[mtehver]

Just for clarification, for geocoding 'setLanguage' it provides both hint and the language/locale of the final address objects. NTAddress itself is a simple container and does not hold any locale-specific info.