Helper functions for DT+Simulation

[oashour]

1. A function to calculate the maximal intensity family given lambda or m. It should return an array of eigenvalues, as well as the relevant shift arrays (maybe, just zeros basically).

2. Function to generate DT based initial condition for simulations

3. Function to generate DT based cosine-series initial condition for simulations

[oashour]

1. and 2. Done in 17349a3