Update the internal docs.

   int nb);

 void bn_mul_low_normal(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n);

 void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,

   BN_ULONG *tmp);

   int dna,int dnb,BN_ULONG *tmp);

 void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b,

   int tn, int n, BN_ULONG *tmp);

   int n, int tna,int tnb, BN_ULONG *tmp);

 void bn_mul_low_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b,

   int n2, BN_ULONG *tmp);

 void bn_mul_high(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, BN_ULONG *l,

arrays B<r>, B<a> and B<b>.  It computes the B<n> low words of

B<a>*B<b> and places the result in B<r>.

bn_mul_recursive(B<r>, B<a>, B<b>, B<n2>, B<t>) operates on the B<n2>

word arrays B<a> and B<b> and the 2*B<n2> word arrays B<r> and B<t>.

B<n2> must be a power of 2.  It computes B<a>*B<b> and places the

result in B<r>.

bn_mul_recursive(B<r>, B<a>, B<b>, B<n2>, B<dna>, B<dnb>, B<t>) operates

on the word arrays B<a> and B<b> of length B<n2>+B<dna> and B<n2>+B<dnb>

(B<dna> and B<dnb> are currently allowed to be 0 or negative) and the 2*B<n2>

word arrays B<r> and B<t>.  B<n2> must be a power of 2.  It computes

B<a>*B<b> and places the result in B<r>.

bn_mul_part_recursive(B<r>, B<a>, B<b>, B<tn>, B<n>, B<tmp>) operates

on the B<n>+B<tn> word arrays B<a> and B<b> and the 4*B<n> word arrays

B<r> and B<tmp>.

bn_mul_part_recursive(B<r>, B<a>, B<b>, B<n>, B<tna>, B<tnb, B<tmp>)

operates on the word arrays B<a> and B<b> of length B<n>+B<tna> and

B<n>+B<tnb> and the 4*B<n> word arrays B<r> and B<tmp>.

bn_mul_low_recursive(B<r>, B<a>, B<b>, B<n2>, B<tmp>) operates on the

B<n2> word arrays B<r> and B<tmp> and the B<n2>/2 word arrays B<a>