added libraries needed for Adafruit components
Added low pass filter to smooth potentiometer readings
Updated header comment and added dial init to startup
Added more UI visual feedback, moved more logic to methods

Added updateWave to draw UI and handle wave and envelope changes.
Added reset of song (press + and x).
Modified pause routine.
Simplified big button logic.
Changed meausre display to one that makes less noise.
Fixed replay bug and changed sad audio
Moved vars to vars.h, fixed bug with setup_env, renamed setup_length to setup_decay
modified default pattern, commented out notes (unused), added synth vars, added new bmp for UI