Fixed fail test
Add file file_loader.lua
Add file_loader_spec.lua
Ad function load to file_loader
fixed fail test in file_loader_spec
Add game_stat_loader
Add module game_stat_loader
Add function 'load' to game_stat_loader
Add more test to initialize_game_stat_spec
Extract mocking loading file error from test function
Add options_initializer_spec
Add options initializer
Load options file from document's directory
Set loaded options to global 'options'
Add default options table when load options file error
Add loading options file at main
Fixed error message in file_loader
fixed fail tests in create_sound_toggle_switch_spec
Rename 'is_sound_enabled' to 'sound_initial_state'
Fixed default value of sound_initial_state