Feature: Gauss-Radau quadratures

Adds the Gauss-Radau quadrature rules (quadrature rules that include either the left or right endpoint of the interval) Also some minor refactoring of the maxima scripts that generate the quadrature rules. The refactoring leaves the output of the scripts, i.e., gauss_imp.hh, jacobi_1_0_imp.hh, jacobi_2_0_imp.hh, gausslobatto_imp.hh unchanged.