option based on file extension + signal gain

- The program now come with preset based on the file extension (tbc, s8, u8, s16, u16, wav, pcm, efm, raw, r8, r16)
- Channel option is now used to override preset option
- new option (set to 8bit) -R8 -G8 -B8  
- new option (disable tbc processing) -not_tbcR -not_tbcG -not_tbcB 
- new option (select the sign) -signR -signG -signB
- new option (add gain to the 8bit value) -SgainR -SgainG -SgainB