Sieve class

A class named sieve and iterator were made to match the implementation of primesieve.org to use in ntheory functions.
Found these articles
http://sweet.ua.pt/tos/software/prime_sieve.html
http://primesieve.org/segmented_sieve.html

"a large interval requires a large amount of memory, which will be accessed in an essentially random way. The cache of modern processors will thus not be used efficiently, making the A constant rather large."

"It (segmented sieve) runs significantly faster than a traditional sieve of Eratosthenes implementation due to its more efficient CPU cache usage i.e. it uses the CPU's L1 data cache size as its sieve array size. This ensures that less than 2 percent of the memory accesses will be cache misses."