Leftover ideas for ODEs

[JordiManyer]

Leftover ideas after #985

TODO

Some Runge-Kutta schemes have the First-Same-As-Last (FSAL) property, that enables sharing a residual evaluation from one step to the next. It may not be possible to have this optimisation in our case because of the Dirichlet boundary conditions.

Ideas for later

• Adaptive time-stepping with embedded Runge-Kutta methods or Richardson extrapolation
• Linear multistep methods (Adam-Bashford, Adam-Moulton, Backward Difference Formula)
• General linear methods
• Numerical methods for differential-algebraic systems of equations (DAEs)