Fix gapple bugs and unload far chunks

bot.py

@@ -51,12 +51,13 @@ def tick(global_state):
 
     target = None
 
-    try:
-        g.chunks.get_block_at(*utils.pint(p))
-    except ChunkNotLoadedException:
+    # make sure current chunks are loaded for physics
+    if not g.chunks.check_loaded(p, 9):
+        packet = serverbound.play.PositionAndLookPacket(x=p.x, feet_y=p.y, z=p.z, pitch=0, yaw=0, on_ground=True)
+        g.connection.write_packet(packet, force=True)
         return
 
-    #g.jobstate.run()
+    g.chunks.unload_chunks(p)
 
     if g.path and len(g.path):
         target = LPoint3f(g.path[0])
@@ -194,7 +195,7 @@ def bot(global_state):
             time.sleep(utils.TICK)
         print('Player loaded.')
 
-        while not g.chunks.check_loaded(g.pos):
+        while not g.chunks.check_loaded(g.pos, 529):
             time.sleep(utils.TICK)
         print('Chunks loaded.')