Joint positioning and rotation code, and fix a problem related to their lua API

Attempt to move the animation system to a more correct implementation, rather than using object properties. Incomplete and breaks functionality

src/content_sao.h

@@ -73,6 +73,7 @@ public:
 	void setTextureMod(const std::string &mod);
 	void setSprite(v2s16 p, int num_frames, float framelength,
 			bool select_horiz_by_yawpitch);
+	void setAnimations(int frame_start, int frame_end, float frame_speed, float frame_blend);
 	std::string getName();
 private:
 	std::string getPropertyPacket();