Expose notes field for purchasing batches

Plus various other tweaks for styles and coding conventions etc.

tailbone/views/purchases/batch.py

@@ -143,6 +143,7 @@ class PurchaseBatchView(BatchMasterView):
         fs.po_number.set(label="PO Number")
         fs.po_total.set(label="PO Total", readonly=True, renderer=forms.renderers.CurrencyFieldRenderer)
         fs.invoice_total.set(readonly=True, renderer=forms.renderers.CurrencyFieldRenderer)
+        fs.notes.set(renderer=fa.TextAreaFieldRenderer, size=(80, 10))
 
         fs.append(fa.Field('vendor_email', readonly=True,
                            value=lambda b: b.vendor.email.address if b.vendor.email else None))
@@ -188,6 +189,7 @@ class PurchaseBatchView(BatchMasterView):
                 fs.invoice_date,
                 fs.invoice_number,
                 fs.invoice_total,
+                fs.notes,
                 fs.created,
                 fs.created_by,
                 fs.complete,