Added the index to first invoice too.
Because of the changes in posting items we now need the index on the first element
in order to be posted.
Removed because there is no more difference if we will post one ore more invoices.
Changed variable into array.
Indented.
Eliminated alert for debugging purposes.
Redirect to the main page if the ajax request is successfull.
Imported functions from utils.
Deleted form dìsaving in the view.
The form will be always posted starting from ajax request.
Commented temporarly actiontaken.
Discussion in place if this field will be part of the main model or not.
Created the basic for the overview/edit view.
Changed the exception to more general error.