Update to fix problems in the demo version

Thank you to all the victims of the “Limb-Severing Devil Case” who are enjoying the full voice demo version!
I have updated the demo version to address some minor issues.

• Changed to not play voices and SEs while skipping to fix a bug that prevented Mac users from skipping voiced dialogues.
  
• The language setting icons on the game startup and configuration screens have been changed to a country-neutral design.
  
• Fixed other minor bugs and typos.