Edit detail for ToDo revision 2 of 2

A short list of things to implement:

• More data structures and general algorithms like red-black trees.
• Fast low level routines like polynomials in algebraic extensions of finite rings (we have U32VectorPolynomials operations but we need more routines in this spirit).
• Faster routines for Smith and Hermite normal forms.
• Numerical routines like high precision numerical integration, high precision solver for ordinary differential equations, routines for numerical computation of special functions (we have a few, but several are missing).
• Improve clef.