Fixes need to restore capability to solve banded systems with nonlinear solver

include/cantera/numerics/BandMatrix.h

@@ -301,6 +301,15 @@ public:
      */
     virtual size_t checkColumns(doublereal& valueSmall) const;
 
+    //! Change the way the matrix is factored
+    /*!
+     *  @param fAlgorithm   integer
+     *                   0 LU factorization
+     *                   1 QR factorization
+     */
+    virtual void useFactorAlgorithm(int fAlgorithm);
+
+
 protected:
 
     //! Matrix data

src/numerics/BandMatrix.cpp

@@ -441,4 +441,10 @@ void BandMatrix::copyData(const GeneralMatrix& y)
     (void) memcpy(DATA_PTR(data), yyPtr->ptrColumn(0), n);
 }
 
+void BandMatrix::useFactorAlgorithm(int fAlgorithm)
+{
+//    useQR_ = fAlgorithm;
+}
+
+
 }