Density-Matrix Renormalization - A New Numerical Method in Physics: Lectures of a Seminar and Workshop Held at the Max-Planck-Institut Fur Physik Komplexer Systeme, Dresden, Germany, August 24th to September 18th, 1998: Lectures of a Seminar and Workshop at the Max-Planck-Institut fur Physik Komplexer Systeme, Dresden, Germany, August 24 to September 18, 1998