Warn for useless lines. (Setting Projectile.damage in SetDefaults)

[JavidPack]

Many things are useless in ModProjectile.SetDefaults, but might mislead a modder in thinking it works and is the correct approach. This warning will prevent users from making these mistakes:

ModProjectile.SetDefaults:
damage -- always overwritten
knockback -- always overwritten
maxPenetrate -- always overwritten
penetrate = 0 -- bug.

ModItem.SetDefaults:
material
Item.ResearchUnlockCount = 1;