1. check parent exist or not in a comfortable way
2. turn all divs that don't have children block level elements into p's
3. score nodes not by all children(util.js line 51 siblings), but 'p' tag only, 'cause all the nodes need score were turned into p on step 2.
Revert "1. check parent exist or not in a comfortable way"

This reverts commit 0252016d13bac675c962a1e2fd66dc3c4c313f56.
check node exist or not in the simple fast way.
considerDIV
Merge pull request #12 from Tjatse/master

considerDIVs