Use some GetMatrix/SetMatrix logic based on SA

# Conflicts:
#	src/control/Pickups.cpp
#	src/control/RoadBlocks.cpp
#	src/core/World.cpp
#	src/entities/Entity.cpp
#	src/objects/CutsceneHead.cpp
#	src/objects/Object.cpp

src/core/Placeable.h

@@ -2,12 +2,13 @@
 
 class CPlaceable
 {
+protected:
+	CMatrix m_matrix;
+
 public:
 	// disable allocation
 	static void *operator new(size_t);
 
-	CMatrix m_matrix;
-
 	CPlaceable(void);
 	const CVector &GetPosition(void) { return m_matrix.GetPosition(); }
 	void SetPosition(float x, float y, float z) {
@@ -20,6 +21,7 @@ public:
 	CVector &GetForward(void) { return m_matrix.GetForward(); }
 	CVector &GetUp(void) { return m_matrix.GetUp(); }
 	CMatrix &GetMatrix(void) { return m_matrix; }
+	void SetMatrix(CMatrix &newMatrix) { m_matrix = newMatrix; }
 	void SetTransform(RwMatrix *m) { m_matrix = CMatrix(m, false); }
 	void SetHeading(float angle);
 	void SetOrientation(float x, float y, float z){