Added cSignEntity into API, added cChunkDesc:GetBlockEntity().

This fixes both #228 and #347.

source/BlockEntities/BlockEntity.h

@@ -49,6 +49,11 @@ public:
 	
 	// tolua_begin
 	
+	/// Creates a new block entity for the specified block type
+	/// If a_World is valid, then the entity is created bound to that world
+	/// Returns NULL for unknown block types
+	static cBlockEntity * CreateByBlockType(BLOCKTYPE a_BlockType, NIBBLETYPE a_BlockMeta, int a_BlockX, int a_BlockY, int a_BlockZ, cWorld * a_World = NULL);
+	
 	// Position, in absolute block coordinates:
 	int GetPosX(void) const { return m_PosX; }
 	int GetPosY(void) const { return m_PosY; }