Rename Delivery.delivered_on to date

This aligns it with column names of StockTaking and us to use inheritance
in a next step to share common code between the entities.

app/views/deliveries/_form.html.haml

@@ -131,7 +131,7 @@
         = render :partial => 'stock_change_fields', :locals => {:f => stock_change_form}
 
   %h2= t '.title_finish_delivery'
-  = f.input :delivered_on, as: :date_picker
+  = f.input :date, as: :date_picker
   = f.input :note, input_html: {size: '35x4'}
   .form-actions
     = f.submit class: 'btn btn-primary'

app/views/deliveries/index.html.haml

@@ -3,13 +3,13 @@
 %table.table.table-striped
   %thead
     %tr
-      %th= heading_helper Delivery, :delivered_on
+      %th= heading_helper Delivery, :date
       %th.numeric= t 'deliveries.invoice_amount'
       %th= heading_helper Delivery, :note
   %tbody
     - for delivery in @deliveries
       %tr
-        %td=h delivery.delivered_on
+        %td=h delivery.date
         %td.numeric= link_to_invoice(delivery)
         %td= truncate delivery.note
         %td

app/views/deliveries/show.html.haml

@@ -3,8 +3,8 @@
 %dl
   %dt= heading_helper Delivery, :supplier
   %dd= @delivery.supplier.name
-  %dt= heading_helper Delivery, :delivered_on
-  %dd= @delivery.delivered_on
+  %dt= heading_helper Delivery, :date
+  %dd= @delivery.date
   %dt= t 'deliveries.invoice_amount'
   %dd= link_to_invoice(@delivery)
   - if @delivery.invoice

app/views/finance/invoices/_invoices.html.haml

@@ -28,7 +28,7 @@
           %td><
             - invoice.deliveries.each_with_index do |delivery, index|
               = ', ' if index > 0
-              = link_to format_date(delivery.delivered_on), [delivery.supplier,delivery]
+              = link_to format_date(delivery.date), [delivery.supplier,delivery]
         %td><
           - invoice.orders.each_with_index do |order, index|
             = ', ' if index > 0

app/views/finance/invoices/show.html.haml

@@ -16,11 +16,11 @@
   %p
     %b= heading_helper(Invoice, :deliveries) + ':'
     %span><
-      - @invoice.deliveries.order(:delivered_on).each_with_index do |delivery, index|
+      - @invoice.deliveries.order(:date).each_with_index do |delivery, index|
         - sum = delivery.sum
         - total += sum
         = ', ' if index > 0
-        = link_to format_date(delivery.delivered_on), [delivery.supplier,delivery]
+        = link_to format_date(delivery.date), [delivery.supplier, delivery]
         = ' (' + number_to_currency(sum) + ')'
 - if @invoice.orders.any?
   %p

app/views/suppliers/show.html.haml

@@ -64,7 +64,7 @@
         %tbody
           - for delivery in @deliveries
             %tr
-              %td= link_to delivery.delivered_on, [@supplier, delivery]
+              %td= link_to delivery.date, [@supplier, delivery]
               %td= link_to_invoice(delivery)
 
   - if @orders.any?