Allow for logging of item data greater than 256.  Fixes #96, #235

This change involves refactoring many instances of ````byte```` to ````short```` and altering a few ItemStack calls to use the ````int,int,short```` form instead of ````int,int,0,byte````
Significantly it also involves altering the MaterialName system to allow shorts instead of bytes, and altering the rawdata() function to return the durability of an ItemStack rather than the data value of its Material.

One side effect of this is that tool durability is now logged, which will make for more accurate rollbacks.