Add Lawson method to SWEET
Write a short timeIntegrator wrapper, performing variable change v = exp(-tL)u, as described in Hockbruck and Ostermann 2010' http://journals.cambridge.org/abstract_S0962492910000048
Write a short timeIntegrator wrapper, performing variable change v = exp(-tL)u, as described in Hockbruck and Ostermann 2010' http://journals.cambridge.org/abstract_S0962492910000048