Add option to set all received items to zero

When an order could not be delivered, this option makes it easy to
set all amounts to zero with only one click.

app/views/orders/_edit_amounts.html.haml

@@ -41,6 +41,13 @@
 
     $(document).on('touchclick', '#order_articles .unlocker', unlock_receive_input_field);
 
+    $(document).on('click', '#set_all_to_zero', function() {
+      $('tbody input').each(function(i, input) {
+        $(input).val(0);
+        update_delta(input);
+      });
+    })
+
     $(function() {
       $('input[data-units-expected]').each(function() {
         update_delta(this);
@@ -97,7 +104,10 @@
       = render :partial => 'edit_amount', :locals => {:order_article => order_article}
   %tfoot
     %tr
-      %th{:colspan => 10}
+      %th{colspan: 6}
         %select#add_article{:style => 'width: 500px;'}
           - new_article_data.each do |option|
             %option{id: "add_article_#{option[:id]}", value: option[:id]}= option[:text]
+      %th{colspan: 4}
+        %button.btn#set_all_to_zero{type: :button}
+          = t '.set_all_to_zero'