Modified simulated test data to include protected status
Modified simulator function to simulate protected status
Modified rvcData to take includes.protected parameter, and to add Protected status to its agg.by attribute
Modified ssu to include LEN in its agg.by attribute
Added function to produce simulated data to test psu function
Modified psu to produce PSU object with length frequency, density, occurrence, and variance in density and occurrence.
Modofied rvcData to properly check for for variable relating to protected status if includes.protected is true
Added test for psu function
Modified test for rvcData to reflect addition of includes.protected parameter
Modified ssu test to expect LEN in agg.by attribute