ENH: comment flagging feature using ajax

1. Comment Flags are done with Ajax calls, bootstrap Modal
2. After flag is received, 'CommentModerators' Groups receives email
ENH: post comments using ajax

1. django.contrib.comments.views.comments.post_comment() is overridden
2. post comment using jquery forms

Features:
1. Asynchronous posting, preview, loading comments

Features not present:
1. form validation on client side