Major rewriting and cleanup of the efficiency approximations (directOff,...
Major rewriting and cleanup of the efficiency approximations (directOff, directOn, lambda), and some of the related sets. Previously, the efficiency approximations required specific efficiency data, and no more than 2 points of data were used. Now the approximations use all the relevant input data they can find (up to the defined maximum indeces) when determining the parameters, and tests have been implemented in "1e_inputs.gms" to abort Backbone execution and warn the user of incompatible input data with the desired approximations. However, without minimum load, there are still issues with the "directOn" and "lambda" approximations that could perhaps be solved.