math.primes: use fast-gcd in coprime? and replicate instead of make.
math.primes: use fast-gcd in coprime? and replicate instead of make.

bpollack/factor,slavapestov/factor,AlexIljin/factor,bpollack/factor,bjourne/factor,nicolas-p/factor,bjourne/factor,dch/factor,bjourne/factor,bpollack/factor,slavapestov/factor,bpollack/factor,tgunr/factor,tgunr/factor,mrjbq7/factor,bjourne/factor,slavapestov/factor,AlexIljin/factor,bjourne/factor,AlexIljin/factor,AlexIljin/factor,dch/factor,tgunr/factor,nicolas-p/factor,factor/factor,bpollack/factor,factor/factor,slavapestov/factor,AlexIljin/factor,bjourne/factor,factor/factor,tgunr/factor,nicolas-p/factor,nicolas-p/factor,tgunr/factor,nicolas-p/factor,nicolas-p/factor,mrjbq7/factor,mrjbq7/factor,nicolas-p/factor,dch/factor,slavapestov/factor,tgunr/factor,AlexIljin/factor,bjourne/factor,bpollack/factor,factor/factor,bpollack/factor,AlexIljin/factor,factor/factor,dch/factor,dch/factor,slavapestov/factor,mrjbq7/factor,factor/factor,dch/factor,mrjbq7/factor,slavapestov/factor,mrjbq7/factor