Fixed MSVC 64-bit build warnings.

src/Simulator/DelayedFluidSimulator.cpp

@@ -148,7 +148,7 @@ void cDelayedFluidSimulator::SimulateChunk(float a_Dt, int a_ChunkX, int a_Chunk
 		{
 			SimulateBlock(a_Chunk, itr->x, itr->y, itr->z);
 		}
-		m_TotalBlocks -= Blocks.size();
+		m_TotalBlocks -= (int)Blocks.size();
 		Blocks.clear();
 	}
 }

src/Simulator/SandSimulator.cpp

@@ -64,7 +64,7 @@ void cSandSimulator::SimulateChunk(float a_Dt, int a_ChunkX, int a_ChunkZ, cChun
 			a_Chunk->SetBlock(itr->x, itr->y, itr->z, E_BLOCK_AIR, 0);
 		}
 	}
-	m_TotalBlocks -= ChunkData.size();
+	m_TotalBlocks -= (int)ChunkData.size();
 	ChunkData.clear();
 }