Preliminary changes for 1.7.2:

- Renamed integer-indexed methods to setValueLegacy
- Sheets don't have a "number" of entries in it, now they use arbitrary string keys
- Data sheets don't get initialized when they are created
- As a consequence, conditions and dynamics don't require a sheet to contain the requested data on initialization --- HOWEVER this has incidence on conditions that will check if something is less than a positive number or equal to zero (or similar), as it will return false instead of true, fix later
- Removed usage of some accessors
- Server data condition checking is more clever, I guess... compares two data sets, and check if they are NOT disjointed.
- Key binding is now in the MISC category, as a placeholder.
- nameOf(Item/ItemStack/Block are not implemented yet
Removed license at the top of every file, as all files in this repository fall under the same license (the code is still under WTFPLv2 though)