interface modification + clean up

Mobility :
- remove unecessary file from transit
- rename Person3 => Person
- add node_destination ini file ( now nodes room choice can be driven
  with an ini file and not only by a random process)

Simul:
- Move from SimPy.Simulation to SimPy.SimulationRT
- Consequently : added a speed ratio option in simulnet.ini

Save 
- Independent process. …
- Simulation results are saved into a dictionnary into S.save.savemat