Inconsistent argument order

[zerothi]

Describe the issue

There are several methods with arguments such as elec, E, k. And their order is not consistent, that is very annoying, and I think it should be changed.

For consistency, I think we should always have the mandatory arguments first.

It is not fully clear to me which is the more natural, I generally think using elec as the first might be the simplest,

k is easy, it should always be optional because the Gamma point is the default.

So I here propose that the argument order should be:

E, elec[, elec_other, k]

for all methods. If there are other mandatory arguments they should probably go in between E and elec because then the elec arguments could be neighboring, which IMHO is logical.

Comments?