Extrapolated BDF (eBDF) Methods

[ranocha]

In nodepy, there is a method eBDF5:

In [1]: from nodepy import *

In [2]: lmm=lm.loadLMM("eBDF5"); print(lmm.alpha); print(lmm.beta); print(lmm.info); print(lmm.name)
[-12/137 75/137 -200/137 300/137 -300/137 1]
[60/137 -300/137 600/137 -600/137 300/137 0]
Explicit 5-step method of order 5
eBDF 5

This method belongs to the class of extrapolated BDF methods, which are based on the idea "interpolate u and differentiate at the next step == interpolate previous f values and evaluate at the next step". It would be nice to implement the general recipe for this family.

Of course, I'm willing to implement this, but it is not my top priority right now. I would just like to open this issue as a reminder.