#349 Support ldi, ldd in gbz80 assembler

[Philipp Klaus Krause]

It would be nice, if the gbz80 assembler would support the alternative
ldi a, (hl) for ld a, (hl+)
ldd a, (hl) for ld a, (hl-)
ldi (hl), a for ld (hl+), a
ldd (hl), a for ld (hl-), a
syntax, since it seems to be very common.

Philipp