Moved entity spawning into cEntity::Initialize().

It has been called in every descendant anyway, so it's better this way - reduced duplicate code.

source/Entities/FallingBlock.h

@@ -29,7 +29,6 @@ public:
 	NIBBLETYPE GetBlockMeta(void) const { return m_BlockMeta; }
 	
 	// cEntity overrides:
-	virtual bool Initialize(cWorld * a_World) override;
 	virtual void SpawnOn(cClientHandle & a_ClientHandle) override;
 	virtual void Tick(float a_Dt, cChunk & a_Chunk) override;