Add comments and delete some unuseful stuff

Add comments and delete some unuseful codes and pictures
Fix url bugs
Fix some bugs

to use the url_for function to generate the urls in templates
Add 404 page
show comments account on index page
Add rss feed
Fix small bugs

Fix css file. Make the website can access the right image.
Add requirements text
Change root of web application
Update index page for blogs

Showing post amount of each category
Remove google code
Merge branch 'master' of https://github.com/jackywjj/flask-blog

Conflicts:
	flaskblog/config.py
remove debug text