Submitting feedback should be a two step process GH2757/2758
When submitting feedback for an event there should be a two-step process - after entering the information and clicking a button - but before submitting for good - a "view" page should show how the feedback will eventually appear, warn the user that once submitted the feedback can't be changed, and allow the user to go back and edit some more. This is pretty standard for feedback and survey forms.
Adding to this, it would be good if we allow edits not just immediately after submitting feedback, but for a short period of time (i.e. there would be an "edit" button on the feedback "view" page).
We also discovered that one can click the "back" button or copy-and-paste the feedback URL to submit multiple sets of feedback. This is undesirable, so we'll prevent that and allow for editing feedback.