Update Writer page, now use lazy loading to load articles
Add Cache, add a storeprocedure, add a alternate local db
Change all but account manager to store procedures; start focusing on saving content
add auto-save and save to cache; todo: add timer to node.js server side and every 5 minutes update article to database, add html column to database, add store procedure to update article and article_version table
fix some bugs, and save html preview into server side
refactor notebook-manager and cache-manager, to make cache-manager the upper layer; fix some bugs in article reading page
fix more bugs
Add auto-saving to database, fix bug in memory cache
fix article page, add sql files