Entanglement entropy and conformal field theory
39 Pages, 10 figures. Review article for the special issue "Entanglement entropy in extended systems" in J. Phys. A. V2 Refs added, typos corrected
39 Pages, 10 figures. Review article for the special issue "Entanglement entropy in extended systems" in J. Phys. A. V2 Refs added, typos corrected