Merge pull request #14 from aboudreault/submit-progress-icon

Submit progress icon
Added FeedbackBlock to get a more flexible control of the popup window.
Added a a section about the feedback child in README.md
Always increase the first right attempt, and always display completed message then
Added font awesome 4 compatibility
Merge pull request #18 from aboudreault/fa4-compatibility

Added font awesome 4 compatibility
Merge pull request #17 from aboudreault/increase-first-right-attempt

Always increase the first right attempt, and always display completed message then
Merge pull request #15 from aboudreault/feedback-child

Added Feedback child
Remove show answer
server-side check to not set completion if the max_attempts is reached
Merge pull request #16 from aboudreault/remove-show-answer

Remove show answer
Remove show answer
Added MRQ hide_results feature
Updated docs
better value check for Boolean
Fix answer validation when read_only is True
readded missing classes for font awesome 4