Please add primecount

Prime counting of sublinear complexity in Common Lisp.
Using sbcl, it can count primes under 10^12 under 8s, which outperforms sympy and PARI/GP.
Also it can sum primes, count primes of the forms 4m+1 and 4m+3.

Author: Aaron Chen
Source: https://github.com/AaronChen0/primecount.git
Documentation: https://github.com/AaronChen0/primecount/blob/master/README.md