Implementad basic curtailability steering to freezer.
Marked other consumptionmodels as curtailable in factory methods.
bugfixes concerning duplicate registration in sim.
Manual merge of workstation and context use from master.
Manual merge.
Manual merging of master branch
Refactored curtailability design to more clean solution.
Cleanup code and some refactoring.
Refactored design of workstation package with more composition in favor of inheretance.
Including test cases for new functionality.
Merge pull request #16 from KrisC369/CurtailableFreezer

Curtailable freezer