Clean up stack.sh config

* Clean up interactive configuration
* Complete moving initialization of service-specific varialbes into the
  service lib/* files.
* Cosmetic cleanups

Change-Id: Iea14359bd224dd5533201d4c7cb1437d5382c4d1
diff --git a/lib/keystone b/lib/keystone
index 17e0866..805cb6f 100644
--- a/lib/keystone
+++ b/lib/keystone
@@ -59,6 +59,9 @@
 KEYSTONE_SERVICE_PORT_INT=${KEYSTONE_SERVICE_PORT_INT:-5001}
 KEYSTONE_SERVICE_PROTOCOL=${KEYSTONE_SERVICE_PROTOCOL:-$SERVICE_PROTOCOL}
 
+# Set the tenant for service accounts in Keystone
+SERVICE_TENANT_NAME=${SERVICE_TENANT_NAME:-service}
+
 
 # Entry Points
 # ------------