UPDATED TO PNG SMASH V1.2

I ADDED SOME QUALITY OF LIFE FEATURES, NOW

 THE OPTION TO OVEWRITE THE ORIGINAL PNG IMAGES BEING COMPRESSED, 

THE OPTION TO SELECT A BASE FOLDER, AND HAVE THE PROGRAM SCAN ALL SUB-FOLDERS FOR PNG IMAGES AND COMPRESS THEM ALL AT ONCE WITH OR WITHOUT OVERWRITE

ADDED A CANCEL BUTTON