added exam preview
get exam questions if exam field of query true
added quiz url
Merge branch 'develop' into client_side_status_check
url tag assigned to decodeURIcomponent of the tags field of the query
changed the button order
changed @query.exam to @options.exam. Now the users dont have access to exam questions.
Merge pull request #21 from RajShah94/client_side_status_check

Admin Preview exam questions and tag selection bug fix