Update to depend on Bukkit 1.5.1-R0.2

Mainly updating for BUKKIT-4004, BUKKIT-3785 fixes.
Update data2Str() with changes from MC 1.5 (#28)

New blocks:
ACTIVATOR_RAIL, QUARTZ_STAIRS, DROPPER, REDSTONE_COMPARATOR_OFF,
REDSTONE_COMPARATOR_ON, HOPPER, QUARTZ_BLOCK

Updated blocks: STEP, DOUBLE_STEP

Also added BURNING_FURNACE data printing
Add QUARTZ_BLOCK to keepData (issue #28)