specified Carry-out for __*shift_1 routines and Sign-out for __llshl_1

[ZERICO2005]

Added documentation to the __*shift_1 routines:

• size and clock-cycles
• input and output parameters
• Specified that the __*shift_1 functions set the Carry flag to the shifted out bit.

I also specified the sign out for the __*shl_1 functions, since every reasonable implementation would output the sign and carry flag anyways. Including a hypothetical __i72shl_1 function:

__i72shl_1:
	add	hl, hl
	ex	de, hl
	adc	hl, hl
	ex	de, hl
	push	bc
	ex	(sp), hl
	adc	hl, hl
	ex	(sp), hl
	pop	bc
	ret

or actually, I guess the sign output could come back to bite us for UIY:UBC << 1

__i48shl_1_uiyubc:
	push	bc
	ex	(sp), hl
	add	hl, hl
	ex	(sp), hl
	pop	bc
	jr nc, .no_carry
	add	iy, iy
	inc	iy
	ret
.no_carry:
	add	iy, iy
	ret