extend localisation with possibility for having mod specific textfiles

[meszaros-lajos-gyorgy]

The game looks for language files in the following format utext_<language>.ini and if a modder wants to extend the language files then he/she has to include all the strings from the original file.
This modification allows modders to add files, like utext_mymod_english.ini or utext_my_custom_mod_english.ini.

The game will load the language files in the following order: utext_english.ini -> utext_mod1_english.ini -> utext_mod2_english.ini

Remaining todos:

• update initLocalisation to glob all mod files after loading the main language file.

[Eli2]

I don't think this is needed the new xtext system should work for that usecase.
Just create a xtext_english_002_mymodname.ini

[meszaros-lajos-gyorgy]

Indeed! Closing PR.