Chunk class improvements:
{A} ChunkDataNeighbourood — to mimic neighbouring chunk array for quick access to other data
{A} customData dictionary, so that filters can store their own per-chunk data
{A} Chunk.toString()
{M} Minor updates to basicStoneAge documentation
{A} WTContext.prepareChunk — optionally called for *all* chunk objects when they land in a worker thread
Improved assertions for Region.ChunkRange
Improved «vectors» documentation; version bump to 0.0.31