Merge pull request #2 from neizod/master

Simplify equation for finding `R_all` in case prime == 2.
removed debug print
Merge branch 'master' of github.com:alexbers/quadratic_sieve
get rid of sqrt_N, looking for other ways
restring the len of smooth array
more test values
more bits in comments
collapsed prive number table
refactor combinations as identity_matrix