* Update keys of rsnvac for first lets
Making it match with what is in the data dictionary. It was a wuick enough
fix to be included in this branch since it pairs well with the newprop derived
variable implementation
* add newprop derived variable and tests
* fixes
* use ternary statement for newprop derivation
* Remove enums
* Add some convenience methods to make validations more readable
* Gender chars instead of ints
* Remove incorrect API doc info for now
* More convenience methods
* Rename label from value method
* Wrapper hbrentshortfall
* Please the cop