Trying to force a specific song length other than the default never quite worked, so we'll only support the default MAX_SAMPLES & will calculate it for the user in the user in the exported .h header file.
Whoever uses it, probably wants their own Patch format, as now it is pretty cumbersome to work with sampleoffsets and delays, as the user needs to construct the delaytimes tables and sampleoffset tables.
audio still a bit crackly; should probably decouple actual row ticking and rendering of audio (but how does that work with tempo ops?)
sequencer goroutine is a bit weird, too, should rethink
