Resolve "Add scenarios"

Closes #9 (closed)

Details

1. Fixed some bugs in Message and SimulationManager
2. Added further Vehicle and InformationBeacon classes for scenario purposes
3. Created 3 scenarios, make sure you pick the right one using the -s flag
4. Moved car and beacon coloring functionality to separate classes, those are in use only for the NYSInfoSharingDemo scenario
   • however beacons receive a gray circle in all cases
5. Refactored MessageScheduler (sorry that I did this here and not in separate branch... just saw further issues with it after creating the information sharing demo scenario)