Removed entanglement between chunks and providers. WARNING: BREAKING API CHANGES.

- All entity and tile constructors now require a \pocketmine\level\Level instead of a \pocketmine\level\format\Chunk.
- Chunk->getProvider() and Chunk->setProvider() have been removed.
- Chunk::__construct() has had the $provider parameter removed.
- Chunk->unload() has had the unused $save parameter removed.
- ChunkEvents now take a Level parameter instead of going through the Chunk

API bump to 3.0.0-ALPHA4

src/pocketmine/level/format/io/region/Anvil.php

@@ -134,7 +134,6 @@ class Anvil extends McRegion{
 			}
 
 			$result = new Chunk(
-				$this,
 				$chunk["xPos"],
 				$chunk["zPos"],
 				$subChunks,

src/pocketmine/level/format/io/region/McRegion.php

@@ -188,7 +188,6 @@ class McRegion extends BaseLevelProvider{
 			}
 
 			$result = new Chunk(
-				$this,
 				$chunk["xPos"],
 				$chunk["zPos"],
 				$subChunks,
@@ -294,9 +293,6 @@ class McRegion extends BaseLevelProvider{
 	}
 
 	public function setChunk(int $chunkX, int $chunkZ, Chunk $chunk){
-
-		$chunk->setProvider($this);
-
 		self::getRegionIndex($chunkX, $chunkZ, $regionX, $regionZ);
 		$this->loadRegion($regionX, $regionZ);
 
@@ -354,7 +350,7 @@ class McRegion extends BaseLevelProvider{
 
 	public function unloadChunk(int $chunkX, int $chunkZ, bool $safe = true) : bool{
 		$chunk = $this->chunks[$index = Level::chunkHash($chunkX, $chunkZ)] ?? null;
-		if($chunk instanceof Chunk and $chunk->unload(false, $safe)){
+		if($chunk instanceof Chunk and $chunk->unload($safe)){
 			unset($this->chunks[$index]);
 			return true;
 		}
@@ -422,7 +418,7 @@ class McRegion extends BaseLevelProvider{
 	 * @return Chunk
 	 */
 	public function getEmptyChunk(int $chunkX, int $chunkZ){
-		return Chunk::getEmptyChunk($chunkX, $chunkZ, $this);
+		return Chunk::getEmptyChunk($chunkX, $chunkZ);
 	}
 
 	/**

src/pocketmine/level/format/io/region/PMAnvil.php

@@ -129,7 +129,6 @@ class PMAnvil extends Anvil{
 			}
 
 			$result = new Chunk(
-				$this,
 				$chunk["xPos"],
 				$chunk["zPos"],
 				$subChunks,