Bit interleaving

[Kevin Ryde]

Torbjorn Granlund <tg at swox.com> writes:
>
> As Kevin pointed out, the right interface for portable code is
> mpz_import and mpz_export.

And incidentally, we're probably amenable to suggestions for
optimizing particular data format cases.  Limb size words in either
endianness are fast, other cases go though some byte-wise
manipulations which should still be pretty reasonable, but not as
fast.