submit button disabled after first submission.
Merge pull request #214 from mahdykhayyamian/disable-button

Submit button disabled after first submission (Issue #154)
Merge pull request #213 from egor83/master

Fixed ID for submissions_list div.
fixing issue #212 : Other reviews aren't displayed for submissions having user's own review
Merge pull request #215 from mahdykhayyamian/master

fixing other reviews aren't displayed for submissions having user's own review
handle exception
check for if self.jeeqser exists.
Merge pull request #217 from anubhavsinha/#216

handle exception
fixing issue #91 : Improve profile image selection on profile pag
fixing issue #91 : set same name for all radio buttons
pdf loading when no description/markdown present
Adding course pdfs
fixing issue #91 : increasing space between radio and profile pictures.
fixing issue #221 : Submission is broken when user has draft.
Merge pull request #227 from mahdykhayyamian/fixdraft

fixing issue #221 : Submission is broken when user has draft.
1- Reducing height of challenge divs in homepage
 2- Don't show avatars when user clicks on jeeqsers submitted number  (only show for jeeqsers solved)
fixing issue #91: applying reviews
fixing issue #201: Flagging is broken for reviews
fix indentation
Changing data models (#226)

(copying fields that refer to votes, to refer to reviews).