* Do not create new NBT objects on Tile::getSpawnCompound()
* PocketMine's string formatting
* Remove more useless array indices and create lesser new NBT objects.
* Remove unused imports and type-hint Sign::setText() params
* Do not mess with Sign::setText() params due to #1204
* Fix formatting
* Make getSpawnCompound() final and add abstract addAdditionalSpawnData()
* Make the same changes for Bed tile
* Fix a missing "->" and remove some unneeded int casting.