Added ScenarioConstants base class for all scenario constants objects
Added ScenarioBase.SerializeToConfigFile()
### Changed
Randomizers now access their parent scenario through the static activeScenario property
Replaced ScenarioBase.GenerateRandomSeed() with ScenarioBase.NextRandomState()
ScenarioBase.Serialize() now directly returns the serialized scenario configuration JSON string instead of writing directly to a file (use SerializeToConfigFile() instead)
ScenarioBase.Serialize() now not only serializes scenario constants, but also all sampler member fields on randomizers attached to the scenario
Steven Leal