add category damapping on damapping page to make comments work

modify include disqus_comments file to support using damapping disqus shortname 'damapping' when first category of page is 'damapping'
only enable comments on already published damapping pages
use page.headline to separate page title from main H1 tag value on homepage
justify text in posts (articles and tips)
diplay tips by first tag in tips page
done TODO add damapping page