unnecessary atomicity code in digitalWrite() and etc.

[WestfW]

The Mega-0 OUTSET and OUTCLR registers are atomic by nature, so interrupts do not need to be disabled in the digitalWrite() code that manipulates them. (code that does &= or |= still needs such wrappers, since all the IOREGes are now outside the SBI/CBI range and will result in non-atomic access.)

	/* Output direction */
	if(port->DIR & bit_mask){

//OMIT		/* Save system status and disable interrupts */
//OMIT		uint8_t status = SREG;
//OMIT		cli();

		/* Set output to value */
		if (val == LOW) { /* If LOW */
			port->OUTCLR = bit_mask;

		} else if (val == TOGGLE) { /* If TOGGLE */
			port->OUTTGL = bit_mask;
									/* If HIGH OR  > TOGGLE  */
		} else {
			port->OUTSET = bit_mask;
		}

//OMIT		/* Restore system status */
//OMIT		SREG = status;

	/* Input direction */
	} else {

[facchinm]

Thanks for pointing it out! Would you mind to post a pull request so you can have the paternity of the commit?

[facchinm]

Fixed by merging #7 , thanks!