* Rework fuzzy comparison for 99 percent threshold
The current implementation is quite convoluted and can handle 99%
incorrectly when items exceed a certain damage range.
* Use metadata explicitly for comparison
Some item could use metadata to pack damageable and undamageable items
into the same id. Thus could lead to get ItemStack#getItemDamage() to
return bogus values for undamageable items.
* Use itemstack as itemdef
* HIGH_TAG/LOW_TAG should be compared both directions
* Remove getTagCompound
* Make Itemlist implementation independent
* Cache item id for performance reasons
* Add preconditions to saveguard against external meddling
* Chache itemDamage
* Remove IAEStackSearchKey for now, rename getDisplayStack
* Extracts item comparison from Platform into their own helper.
Renamed methods to be more more fitting for the actual comparison.
Added documentation about each methods behaviour.
yueh