added pagination on board.
modified some url patterns. On existing url patterns that differs link to listing articles from that to viewing article, because they load same templates, we need to code same logic twice on each request. so I decide to make viewing article processed in the request of listing articles. therefore, the url patterns for it is removed and id of wating article is moved through arguments of listing url.
modified processes on writing new article and comment.
Merge branch 'new/board' into devel