Text commenting flow for a11y

[kimisgold]

The ajax branch submits the comment form via ajax and more easily allows screen reader friendly notifications. Please test the following on an item show page:

• Comment on an item. Navigate to the commenting form via keyboard.
• Each field on the comment form should be properly labeled and read by the screen reader.
• When a comment is successfully submitted, the screen reader notifies the user.
• Submitted comments can be flagged for removal, as well as unflagged. The screen reader should announce the comment state when this happens.
• Users can reply to comments. Activating the reply link should place the comment form immediately under the reply target, and then focus on the first field of the commenting form.