Added V0.8 code

Changes from V0.8 and V0.7 mod:
-Some monsters can detect the player from a much greater distance.
-Zombie Pigman have a shorter detection field radius and do less damage.
-Zombie Pigman drop 1-2 Gold Nuggets and 1-2 Rotten Flesh instead of 0-1
of each.
-Fixed minor bug where Zombie Pigman speed isn't consistent.
-Ghast fire-rate increased; decreased Ghast fireball explosion power
from 3 to 2 (default is 1).
-Cave Spiders poison on any difficulty; poison length slightly
increased.
-Cave Spider's Hunger effect has been weakened slightly.
-Creepers are more aggressive. They can explode even if they don't see
you, and they cannot stop their fuse once it is started.
-Skeletons shoot faster.
-Blazes can spawn anywhere in the Nether.
-Blazes may spawn fire blocks.
-Spiders and Cave Spiders may spawn web blocks.
-Silverfish give brief Weakness II and Nausea effects.