and TestPolynomialSolvers to TestPolynomialSolversUnivariate.
ENH: Various improvements to the Sturm solver from Korben Rusek,
     including control over the interval type (open, closed, or half-open),
     more robust polynomial division, and a routine to evaluate the
     derivatives of a polynomial at roots to verify that they are solutions
     and not merely local minima/maxima near zero.
ENH: More testing.