Class PrimitiveBlock

NOTE: currently relations are stored, but we don't wait for the Block to store all relations before we start testing primtiveHandle against the data. This is a problem because relations reference eachother at times, and we need to be able to resolve those references before we can run relationHandle against the data. This isn't an important issue since in practice, all relations that reference eachother often produce garbage or unusable data. But it would be nice to fix this. Morbidly enough, the "BEST" solution is to treat relations like we do nodes and ways since relations could possibly reference eachother outside their own block. From a practical standpoint, I can't see this being worth the effort or memory/time cost.