Removed references to Matsubara in the superclass Changed the N_m attribute to N_exp to be more general
Removed references to Matsubara in the superclass
Changed the N_m attribute to N_exp to be more general

cgranade/qutip,anubhavvardhan/qutip,cgranade/qutip,qutip/qutip,anubhavvardhan/qutip,qutip/qutip