bitbake: toaster: bring django-aggregate-if into the project

We bring the django-aggregate-if module (with minor changes to import)
into the project.

(Bitbake rev: 4b92add34167304b45c66b9726cbc64bc0f74d9f)

Signed-off-by: Alexandru DAMIAN <alexandru.damian@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/toaster/contrib/django-aggregate-if-master/aggregate_if.py

@@ -10,7 +10,7 @@ This code was based on the work of others found on the internet:
 4. https://groups.google.com/forum/?fromgroups=#!topic/django-users/vVprMpsAnPo
 '''
 from __future__ import unicode_literals
-import six
+from django.utils import six
 import django
 from django.db.models.aggregates import Aggregate as DjangoAggregate
 from django.db.models.sql.aggregates import Aggregate as DjangoSqlAggregate

bitbake/lib/toaster/toastermain/settings.py

@@ -393,3 +393,12 @@ class InvalidString(str):
             "Undefined variable or unknown value for: \"%s\"" % other)
 
 TEMPLATE_STRING_IF_INVALID = InvalidString("%s")
+
+import sys
+sys.path.append(
+    os.path.join(
+    os.path.join(
+        os.path.dirname(os.path.dirname(os.path.abspath(__file__))),
+            "contrib"),
+            "django-aggregate-if-master")
+    )