Added fields to attendees as requested by TEDx. Two tests are still failing as it is the case in master.
See Trigger #10662: Fixed the build.
See Trigger #10662:
* Added new mail event when a user declines his attendance so that he does not receive the same message as the one he receives when an admin declines for him.
* The email sent when an admin decline an attendance is now the same as the one sent when revoking an invitation.
Submission form styles
Updated email content from Lisa
See Trigger #10662:
* Added the possibility to have a student price in the booking system.
See Trigger #10662:
* Tests for the possibility to have a student price in the booking system.
[T10727] TEDx - Additional styling
Merge pull request #29 from net-engine/tedx_feedback

Tedx feedback