READ ARRAY - read a range of bytes

 Command:       $AF $0F
 Data:          $ww $xx $yy $zz $qq $rr $ss $tt

 read a range of bytes from address <$wwxxyyzz> for <$qqrrsstt> bytes
 Will return that number of bytes...

 Command will be ACK'ed when received.
 Command ACK:   $00 $0F
 Command DONE:  $1F $0F $uu [$uu ...]