Bugfix: added missing 'break'
Changed internal gate time variables from 64b to 8b
Bugfix: div() takes int, not uint64_t...

facepalm.
Added divmod functions to misc.c

We don't actually use them here (yet - who knows, but no point in losing
the code I wrote)
Switched instrument code to object-based structure

Allows for much more graceful implementation of multiple instruments
(two channels!). Also makes the compiled code smaller ^-^