Storage updates

[kilianp14]

• Updated co-simulation infrastructure to avoid wrong order of execution of simulators by mosaik
• Updated way of setting storage/policy parameters during simulation. Now parameters are set from controllers in the following way: self.set_parameters["policy:charge_power"] = 10 or self.set_parameters["storage:min_soc"] = 0.3
• Former actor_infos passed to controllers every step is now state and also contains the storage and policy state next to the actor states (This is not yet updated in the SilController)
• Storage api has been updated to represent the paper version and now uses Wh instead of Ws both externally and internally:
  storage = vs.SimpleBattery(capacity=1500, initial_soc=0.8, min_soc=0.5)
• SimpleBattery soc and min_soc should now no longer be sensitive to floating point operations (closes SimpleBattery is sensitive to floating point imprecision #204)
• Examples have been updated, but still need a bit of work
• Small fixes and updates in the sil example
• Updated tests and documentation (closes Improve documentation of storage module #117)

[marvin-steinke]

Aight this PR looks like a biggie, lets talk in the meeting haha

[marvin-steinke]

does this matter?