rm add_vote in model Answer

remove useless debug print
mv .hidden class to base.css
add answer vote urlpattern
template view for vote
Update README.md
change datetime format
rm  css boxshadow effect
move js link before </body>
structure js file properly

rm unused js library  and template
mv script from html,  create modal popup tools js
put script after dependent js library
ajax vote unvote
add ajax-loading gif
asquestion: ajax-loading class