Updated for Acacia and Dark Oak

ACACIA at 2.0 in hot_dry, 1.0 in PLAINS

DARK_OAK 2.0 in swamp, 1.0 in forest, 0.5 in cold_forest

Both inherits from tree and overwrites defaults biomes to 0.
Merge pull request #8 from ribagi/patch-2

Updated for Acacia and Dark Oak