[WIP][RC] change language

The goal is to change the language on run-time. 

STATUS: after restart all translatable strings except the strings used in initOptions use 
the selected language. initOptions is called before the language is set and uses the system language. 

TODO: 
* solve chicken egg problem,  access USE_LANG option before strings in initOptions are stored translated
* build list of languages on start
* update windows and stored translated strings