Changed the calculations of sum totals to be raw SQL queries for speed boost. Not ideal but the best we are going to get.

Changed outstanding invoice to a raw SQL query for a speed boost. Average load now ~3.5s with ~10 invoices

RIGS/migrations/0019_auto_20150131_1919.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('RIGS', '0018_auto_20150130_0016'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='payment',
+            name='method',
+            field=models.CharField(blank=True, max_length=2, null=True, choices=[(b'C', b'Cash'), (b'I', b'Internal'), (b'E', b'External'), (b'SU', b'SU Core')]),
+            preserve_default=True,
+        ),
+    ]

RIGS/migrations/0020_auto_20150303_0243.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('RIGS', '0019_auto_20150131_1919'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='payment',
+            name='method',
+            field=models.CharField(blank=True, max_length=2, null=True, choices=[(b'C', b'Cash'), (b'I', b'Internal'), (b'E', b'External'), (b'SU', b'SU Core'), (b'T', b'TEC Adjustment')]),
+            preserve_default=True,
+        ),
+    ]