Lua: add callins FeatureDamaged and FeaturePreDamaged
  FeatureDamaged(
    number featureID, number featureDefID, number featureTeam,
    number damage
    [, number weaponDefID, number projectileID
    [, number attackerID, number attackerDefID, number attackerTeam ]]
  )

  FeaturePreDamaged(
    number featureID, number featureDefID, number featureTeam,
    number damage
    [, number weaponDefID, number projectileID
    [, number attackerID, number attackerDefID, number attackerTeam ]]
  )