miscellaneous improvements
miscellaneous improvements

The inefficient implementation of Integer.Exponentiate for fractional exponents is still there, but I now avoid invoking it in LinearlyIndependentSum.RefineMagnitudeErrorInterval by constructing Surds directly rather than through Integer.Exponentiate. These Surds may be degenerate, but for the purposes of invoking their numerical approximation code, this isn't a problem. The input 2^(1/2)+3^(1/2)+(5+2*6^(1/2))^(1/2) now returns 2*2^(1/2)+2*3^(1/2), as desired.
AlexanderKindel/solver,AlexanderKindel/solver