data_reduction_proxy_params.{h,cc} and _switches.{h,cc} contain information needed to retrieve experimental variations configurations and command like switches. Instead, all access to experiments and switches should be via a single file of static methods. 

For lack of a better name, let's call it "experiments.h"


The methods in this file should provide information about how to configure the feature, and should not provide methods that return strings to access variations configurations and the command line directly.