Fix bug in mp_div_2d that set r = q % d when a and q are the same mp_int. Minor performance enhancement to s_mp_div_2d when DIGIT_BIT divides d.
Fix bug in mp_div_2d that set r = q % d when a and q are the same mp_int.
Minor performance enhancement to s_mp_div_2d when DIGIT_BIT divides d.

thespooler/nss,thespooler/nss,thespooler/nss,thespooler/nss,thespooler/nss,thespooler/nss,thespooler/nss