Fetch news from urls.

Fetch depth: 1

There files need to be modified while add a new site:

• main.go: add entrance url
• links.go -> SetLinks(): add case about target urls feature regex, eg: if url must have about, param 2 is .*?about.*
• site/newsite: copy files from sibling folder, then develop and pass the test.
• post.go -> TreatPost(): add case for new site domain.