Using more bukkit interfaces rather than IDs

Item/damage/anything ID's have now become deprecated in bukkit presumedly
in preparation for any sort of official server modding API. This switches
war from using IDs in most cases to bukkit-provided classes such as
ItemStack.
Fixes gh-640 - Glassify a list of block types

Other block types than AIR and WATER are now automatically "glassified" by
the warzone wall guard.