A lot of changes

- Fix the broken itemindex of ComboBox  in the Settings dialog
- Change from LCID to uint32_t
- Rewrite the headers of the lang related functions (can handle the whole LCID as input)
- Add dummy functions to unix.c
- Add proper combobox handling in win_settings.c
- Added a lot of debug calls temporarily
- Reactivate every disabled option related to language changes
- Move lang_id to 86box.h from win.h
- Implement on-fly resource switch as discussed with OBattler
- Reimplement everything language related in the initialization section of the program
- Implemented the ladder of three points
1, what is the --lang?
2, what are definied in the config? (to be implemented)
3, what is the system language

src/include/86box/plat.h

@@ -15,6 +15,7 @@
  *
  *		Copyright 2016-2019 Miran Grca.
  *		Copyright 2017-2019 Fred N. van Kempen.
+ *		Copyright 2021 Laci bá'
  */
 #ifndef EMU_PLAT_H
 # define EMU_PLAT_H
@@ -121,10 +122,10 @@ extern void	plat_setfullscreen(int on);
 extern void	plat_resize(int x, int y);
 extern void	plat_vidapi_enable(int enabled);
 extern void	plat_vid_reload_options(void);
-extern int plat_set_language(char* langcode);
+extern uint32_t plat_language_code(char* langcode);
 
 /* Resource management. */
-extern void	set_language(int id);
+extern void	set_language(uint32_t id);
 extern wchar_t	*plat_get_string(int id);