added and changed form fields, changed mockup import in rest client

Added a function to update the changes made to the list settings and added missing <form>-parts in settings.html.

Created one massive form for the settings page.

Corrected the decorators and started with the settings view and forms.

Changed function names and calls in the view to make it work with the new rest-client. ...

Added the possibility to use fieldsets and divs in forms, by using as_div in the form.

Initial commit, added unsubscribe possibility to Florian's branch.