Updating stepper pulse width for compatibility with newer high current stepper drivers.

Figured I'd add comments about how to make this code compatible with the DRV8825. Should save someone a bit of time figuring out why steps are being skipped. I have tested this and it works smoothly.

For anyone having trouble getting high current stepper motors to work in the future: MAKE SURE YOU READ THE SPEC SHEET. That is all.

Note: This will affect the BreakoutJS web interface acceleration/speed calculation.