update fixture and model of qa
add no answer category and tags in qa module.
Add question.html
add hover event.
add global js method(window.flash_message) to flash message.
Merge branch 'duplicate/flash-message-method' into feature/question-system
modified base.styl and dropdown.stl
Merge branch 'duplicate/styles' into feature/question-system
static files for up/down vote, answer question form.
add isdeleted column in qa model.
add question coffee script
add view func in qa/view.py, vote func and answer question
add ajax with cookie js in base.html, fix code style/
add a link to lecture if the question ask in lecture page.
add ask question page.
show lecture's questions
ask question with lecture id
Update fixture.py
Merge branch 'feature/question-system' into develop