deferred style: use a generator for the list of report section

This uses much less memory

bt5/erp5_deferred_style/SkinTemplateItem/portal_skins/erp5_deferred_style_core/Base_report.xml

@@ -64,14 +64,14 @@ with portal.Localizer.translationContext(localizer_language):\n
 \n
   report_section_list = [r.getResult() for r in ap.getResultList()]\n
   assert len(report_section_list) == report_section_count\n
-  report_section_list.sort(lambda a, b:cmp(a[0], b[0]))\n
+  report_section_list.sort(key=lambda x: x[0])\n
   \n
   def dummyReportMethod():\n
     return report_section_list\n
 \n
   report_data = context.restrictedTraverse(form_path).report_view.pt_render(\n
       extra_context=dict(options={\'format\': format},\n
-                         rendered_report_item_list=[r[1].decode(\'zlib\') for r in report_section_list],\n
+                         rendered_report_item_list=(r[1].decode(\'zlib\') for r in report_section_list),\n
                          report_method=dummyReportMethod,\n
                          form=portal.restrictedTraverse(form_path)))\n
 \n
@@ -82,6 +82,7 @@ with portal.Localizer.translationContext(localizer_language):\n
     attachment_name = attachment_name[1:]\n
   if attachment_name.endswith(\'"\'):\n
     attachment_name = attachment_name[:-1]\n
+\n
   attachment_list = (\n
     {\'mime_type\': (request.RESPONSE.getHeader(\'content-type\') or \'application/octet-stream;\').split(\';\')[0],\n
      \'content\': \'%s\' % report_data,\n