First batch:
* Initialize blocks somehow, so no errors nor missing blocks happen
during startup.
Possibly Missing:
* There might be references of removed/renamed material (blocks/items)
throughout the code.
* Some blocks may behave different now/then.
Missing:
* Block#getData may not reflect (all?) properties anymore.
* Block shape getting is missing. Block shapes are now (potentially)
more complex to process. Concept might be to keep a double array for the
rough bounds, and add an (optional +- null) array of arrays for sub
shapes, if present (IBlockCacheNode). So a first rough update is more
simple/compatible.