Writing documentation on DenseMatrix.

Documentation/Examples/Matrices/CMakeLists.txt

...ation/Examples/Matrices/DenseMatrixExample_addElement.cpp

...tation/Examples/Matrices/DenseMatrixExample_addElement.cu

...Examples/Matrices/DenseMatrixExample_allRowsReduction.cpp

.../Examples/Matrices/DenseMatrixExample_allRowsReduction.cu

...entation/Examples/Matrices/DenseMatrixExample_forRows.cpp

...mentation/Examples/Matrices/DenseMatrixExample_forRows.cu

...ation/Examples/Matrices/DenseMatrixExample_getElement.cpp

...tation/Examples/Matrices/DenseMatrixExample_getElement.cu

...on/Examples/Matrices/DenseMatrixExample_rowsReduction.cpp

...ion/Examples/Matrices/DenseMatrixExample_rowsReduction.cu

...ation/Examples/Matrices/DenseMatrixExample_setElement.cpp

...tation/Examples/Matrices/DenseMatrixExample_setElement.cu

src/TNL/Matrices/DenseMatrix.h

src/TNL/Matrices/DenseMatrix.hpp