addition of mp_expt (all input bigint)

[czurnieden]

An exponentiation function like mp_expt_d but with all input having the type mp_int.
Needed for low-MP.

The test for this function will time-out because it uses the original mp_n_root_ex function. Works well with the version in #189

[czurnieden]

Mmh…for some reason the function to add the leading and trailing comments to the new files in dep.pl doesn't work anymore? The backslashes for the dollar signs in the end-comment gets printed! Works without the backslashes. WTF?
And who did it? Oh, me. *grrr*
OK, will check it out.

[czurnieden]

Ah, that was mean! ;-)
Oversaw the single quotes

[minad]

@czurnieden Would it make sense to instead extend mp_expt_d_ex/mp_expt_d to accept larger exponents than mp_digit (maybe call them mp_expt_int_ex/mp_expt_int)? Then we could avoid this function.

[czurnieden]

Would it make sense to instead extend mp_expt_d_ex/mp_expt_d to accept larger exponents than mp_digit (maybe call them mp_expt_int_ex/mp_expt_int)?

I found no easy way to do so.
And as most people use the "normal" expt_d function, the bigint one is more for the low-mp users, especially the 8-bitters, I made it a separate function instead that you can exclude from the build if you don't need it.
But, as hinted on above: if you find a neat way to merge those two, I would be all in for it.

[minad]

@czurnieden This one can be closed right? Instead we want mp_expt_int or a simpler version which just takes the lowest bits of the exponent. See #243 and #240 for previous discussions.