gen app: quick selection of primes for faster factorization testing.
Dixon: starting to play with multiple cores. GROW BABY
Back to printing the RSA private key in PEM  when in debug mode.

Try it!
$ ./src/qa -f ./src/questions/tests/pollard.pem | openssl rsa -text
NotBefore and NotAfter fields in metadata question.

Almost copied from ASN1_TIME_print(), but this shitty openssl does not have any
function for placing the result into a string.