* Have BrokerageModel determine default benchmark
* Add DefaultBenchmark to Python wrapper
* Handle Null benchmark case
* Add NullBenchmarkRegressionAlgorithm
* Refactor solution to have BrokerageModel return IBenchmark; also refactor QCAlgorithm benchmark handling
* Always create a new security for benchmark
* Drop security overload, Always create a new security for benchmark
* Check our securities for a symbol matching the ticker before creating a new one
* No Python version of this regression
* Address review
* Create shared SecurityBenchmark creator function
* Add Python regression and needed FuncBenchmark constructor
Colton Sellers