CORD-1345: Rename PlCoreBase to XOSBase

Change-Id: I97797031d33fffcf482c2d209ed8532932cde56a
diff --git a/xos/header.py b/xos/header.py
deleted file mode 120000
index 721b5c0..0000000
--- a/xos/header.py
+++ /dev/null
@@ -1 +0,0 @@
-attic/header.py
\ No newline at end of file
diff --git a/xos/header.py b/xos/header.py
new file mode 100755
index 0000000..99a1818
--- /dev/null
+++ b/xos/header.py
@@ -0,0 +1,27 @@
+from django.db import models
+from core.models import Service, XOSBase, Slice, Instance, Tenant, TenantWithContainer, Node, Image, User, Flavor, NetworkParameter, NetworkParameterType, Port, AddressPool
+from core.models.xosbase import StrippedCharField
+import os
+from django.db import models, transaction
+from django.forms.models import model_to_dict
+from django.db.models import *
+from operator import itemgetter, attrgetter, methodcaller
+from core.models import Tag
+from core.models.service import LeastLoadedNodeScheduler
+import traceback
+from xos.exceptions import *
+from xos.config import Config
+
+
+class ConfigurationError(Exception):
+    pass
+
+
+VROUTER_KIND = "vROUTER"
+APP_LABEL = "vrouter"
+
+# NOTE: don't change VROUTER_KIND unless you also change the reference to it
+#   in tosca/resources/network.py
+
+CORD_USE_VTN = getattr(Config(), "networking_use_vtn", False)
+