Clean up + save function

# Mobility
+ remove unecessary file from transit
+ rename Person3 => Person
+ add node_destiantion 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
+ Save is now an independent process.
+ Simulation results are saved into a dictionnary into S.save.savemat

and last but not the least 

+ Brand new Matlab structures output  
![pylayers matlaboutput](https://f.cloud.github.com/assets/1019656/149379/f9786ff8-752b-11e2-8063-efafc0ed3908.jpg)