use Miller-Rabin not trial division for small prime check
use Miller-Rabin not trial division for small prime check

since multiple people have verified that there are
only few bases necessary in Miller-Rabin test
to prove primality of small (<2**64) numbers, use
MR instead of trial division to verify primality
of the number from the last step of the ECPP certificate
verification

tomato42/ecpp-verifier,tomato42/ecpp-verifier