A few updates

o Addon models now more complete.
o Uanisohyper_inv updated and test made
o runtime opts now a class
o plotting does not work with tests right now - due to a failure in
  matplotlib.
o import material so lib in setup function now in most materials
Misc updates

o simulation_dir in runtime.opts
o core.material: initial jacobian time step set to 1 not 0
o utils.misc: better file import
o core.simultor: better error catching from np.linalg
o others