Need to handle extra data when dealing with report copyright

[tbinetruy]

Currently, a user can report a song as copyright infringement by clicking on the three dots icon to open the bottom tray and clicking on 'Copyright infringement'. A POST request is then sent to the server to create an entry on /api/statuses/ linking the user making the request, the song being marked as copyright infringement, and a status (copyright infringement in this case, but it could be report spam or like the song).

The problem however, is that we now want to require the user to post a few information about why he is marking such a song as copyright infringement. Soundcloud does that as well with this form:
http://soundcloud.com/pages/copyright/report/form

Therefore, what is needed in the API is a way to POST a form associated to a song when reporting it as copyright infringement.

The fields needed (for now) are the following:
The song ID (already done)
The user reporting the song (already done)
How the user is involved with the song (integer representing a string (copyright owner, authorized agent etc)
a textarea for detailed explanation (string)
First & last name (string, real first name of person associated with request)
address (street, city, zip, country)
email
telephone number
signature field (cf. soundcloud form)