add href in date to edit article
FIX:tips page:tag=>tag.name
Merge branch 'dev' into edit
add basic edit function

TODO:add edit href in single article page. should add login judge in
every view
FIX:tips.html tips==>tips|safe
FIX:edited article will overwrite the fromer one , not create new one.
Merge branch 'dev' into edit
FIX:content string=>Text
FIX:pub_date will add 8 hours every time save article
ADD:login decorative method
add robots.txt
article title length adjust
add baidu script
hide baidu img
post tips need no login
added save button

1.added save button
2.if title is blank , give a error msg
3.give reminder if submit/save success