this parameter was previously used to send blocks with a different set of flags, immediately, to players. However, the flags have been demonstrated useless and the direct sending is pointless now since packets are buffered now per session, so we might as well take advantage of the batched block update sending.
These flags are not intended for network use, instead they are supposed to be used internally by the game. For network, we only need to care about the 0x02 flag (send to players) because that's necessary for the client to render the block.
readline on Windows causes issues with console output corruption. Additionally, PM readline impl is extremely buggy and probably ought to be removed. However, have a hotfix for now.
This is only implemented in 1 place where the collision box should just be zero anyway, so there's no point this existing.
There's a lot of other blocks which should have bounding boxes without collision boxes as well, but that's outside the scope of this commit.
this will be necessary to deal with negative IDs (if I choose to do that), and it'll also be necessary if I decide to do any shift hacks to merge ID/variant for block IDs, because we don't want such things to affect items before we're ready to deal with that.
This is a major change to the way block metadata is handled within the PM core. This separates variant metadata (which really ought to be part of the ID) from state metadata, and in a couple of cases flattens separate states of blocks together.
The result of this is that invalid variants can be much more easily detected, and additionally state handling is much cleaner since meta is only needed at the serialize layer instead of throughout the code.
