Add null space task for IK.

examples/ThirdPartyLibs/BussIK/MatrixRmn.h

@@ -131,6 +131,8 @@ public:
 	bool DebugCheckSVD( const MatrixRmn& U, const VectorRn& w, const MatrixRmn& V ) const;
     // Compute inverse of a matrix, the result is written in R
     void ComputeInverse( MatrixRmn& R) const;
+    // Debug matrix inverse computation
+    bool DebugCheckInverse( const MatrixRmn& MInv ) const;
 
 	// Some useful routines for experts who understand the inner workings of these classes.
 	inline static double DotArray( long length, const double* ptrA, long strideA, const double* ptrB, long strideB );