Temporary fix for a weird bug.
Install zeroclipboard.
Add a simple copy button.
Give some visual indication when after copying.
Make ZeroClipboard play well with Turbolinks.
Add JSON column to tasks.
A JSON checkbox to problems form.
Show task input in multiple fields if it is mark as JSON input.
Refactor task inputs.
Stylize the input fields.
Write docs for JSON input.
Automatically infer whether input is multiline or not.
Properly render the task input in submission detail page.
Remove the copy buttons when flash is not available.