8-13

1.Optimize filtering module. Add a new class RandSeq to generate random
sequence to filtering random noise.
2.Rewrite construct module. Now postive and negtive regulation are no
longer calculate together. The module consider them separately. And
choose the more significant one to predict new relationship.
Merge pull request #5 from ustckun/master

8-13 kun
Merge pull request #16 from jinyangustc/master

8-13