"sfx(-1)" is required before playing same sound, duration parameter to sfx api.

[AnastasiaDunbar]

Even have to use sfx(-1) as an initializer.
Also using a value greater than 4 (or less than 0) for sfx channel then the application will crash.

[nesbox]

will fix and try to make sfx easier
thanks

[trelemar]

I'm gonna merge the other issue from here as they're very similar and relate:
#98

[nesbox]

you don't need to call sfx(-1) to stop playing sfx before start a new, it fixed since .22

• but app still crashes if channel less than 0 or greater than 3
• also I'm going to add duration parameter

[nesbox]

added duration parameter
sfx id [ note [ duration [ channel [ volume [ speed ] ] ] ] ]
note - is absolute note = octave * 12 + note or string like "C#4"
duration - how many ticks to play sfx = -1 by default, to play sfx infinitely

done on .23