Fixes #80, fixes #355, fixes #258

#80 is fixed by removing the vanilla recipes for stairs
#355 is fixed by using setBlockToAir instead of setBlock to 0
#258 is fixed by instead of using the zombie attackEntityFrom(DamageSource par1DamageSource, float par2) which would spawn vanilla zombies to use the EntityLivingBase attackEntityFrom(DamageSource par1DamageSource, float par2)