Long Cytoid Wall Duplication Glitch

[Clashsoft]

The Long Cytoid Wall block places two blocks in the world when placed (upper and lower half), both of which can be mined and will drop another Long Cytoid Wall block item. This can be exploited to duplicate the items by repeatedly mining them. There are four ways to solve the problem:

• Add two separate items, lower and upper half, and place only one block.
• Keep one item, but only place one half and smartly decide if it displays as the upper or lower part.
• Only drop when either the lower or the upper half is mined.
• Destroy the other half when either the lower or the upper half is mined (doesn't work well with pistons).

[Delocuro]

Try looking at the code for how double-tall flowers do their break detection — I'm thinking making them work like that would be best (breaking either half of the block breaks both and drops one item). As far as pistons go, we could try to make them work like pushing a slime block located next to another block, where the other half will move as well, or neither half will if either is blocked — shouldn't be too hard to figure out, but if it is we can just make them unpushable or something.