BN_mod_exp_mont does not work properly yet if modulus m
is negative (we want computations to be carried out
modulo |m|).

(just in cases someone uses a negative modulus)

it is missing.

"xxx tests passed" message.

stderr...

not just on certain platforms.

reliable timings yet, please try it out!

Spotted by plin <plin@rainbow.com>

add debug output facilities.

really undefined.
Spotted by Jeffrey Altman <jaltman@columbia.edu>

course, that means we need to handle the cases where the two arrays to
bn_mul_recursive() and bn_mul_part_recursive() differ in size.

I haven't yet changed the comments that describe bn_mul_recursive()
and bn_mul_part_recursive().  I want this to be tested by more people
before I consider this change final.  Please test away!

so these macros probably shouldn't be used like that at all. So, this
change removes the misleading comment and also adds an implicit trailing
semi-colon to the DECLARE macros so they too don't require one.

will probably be more when the lh_doall[_arg] callbacks are similarly
tidied up, but this 'pod' should now be current.

cases of function pointer casting in lh_new() calls - and leave only the
lh_doall and lh_doall_arg cases to be finished.