Crystal clean PCM 8bit samples on the poor PSG

Thank you.
Is this the last version?

@aoineko
Let me know if you have problems with the ecoder. I think I could also simplify its output in order to get only output files for the msx PSG (now it floods the user with data to be used in ASM on MSX with PSG and SCC and on Intellivision in intybasic).