this unpleasantly-named method allows controlling the source-forming behaviour of liquids by changing the required number of adjacent sources that must be present in order for a new source to form. This allows stuff like non-infinite water.
this fixes TNT spawning multiple entities when lit by flaming arrows.
The problem here is a bit more complex (entities aren't immediately notified when local block updates happen, so they cache stuff that becomes unusable). The simplest option would be to just lose the cache, but that would have some impacts on performance.
Barring a rethink of the block updating mechanism, this solution seems usable for now.
