Update scroll tool with changes from MC 1.5 (#28)

New blocks:
ACTIVATOR_RAIL, QUARTZ_STAIRS, DROPPER, HOPPER, GOLD_PLATE, IRON_PLATE,
REDSTONE_COMPARATOR_OFF, REDSTONE_COMPARATOR_ON, QUARTZ_BLOCK,
TRAPPED_CHEST

Updated blocks: STEP, DOUBLE_STEP, DISPENSER

Also allow BURNING_FURNACE to be scrolled