CORD-1345: Convert plcorebase to xproto and rename it to XOSBase

Change-Id: I0fd4c31a56a4ed79f781345185a9f971399367f0
diff --git a/xos/attic/header.py b/xos/attic/header.py
index afa4e4c..7ecc68a 100644
--- a/xos/attic/header.py
+++ b/xos/attic/header.py
@@ -1,7 +1,7 @@
 from django.db import models
 from django.db.models import *
-from core.models import Service, PlCoreBase, Slice, Instance, Tenant, TenantWithContainer, Node, Image, User, Flavor, TenantRoot, NetworkParameter, NetworkParameterType, Port, AddressPool, User
-from core.models.plcorebase import StrippedCharField
+from core.models import Service, XOSBase, Slice, Instance, Tenant, TenantWithContainer, Node, Image, User, Flavor, TenantRoot, NetworkParameter, NetworkParameterType, Port, AddressPool, User
+from core.models.xosbase import StrippedCharField
 import os
 from django.db import models, transaction
 from django.forms.models import model_to_dict