SEBA-419 allow legacy to be specified on a per-model basis;
Deprecate "legacy" in favor of "custom_python"

Change-Id: I44625ff18ee7796996ae25ad700e58a0b36e7398
diff --git a/Makefile b/Makefile
index 7823757..c1f9032 100644
--- a/Makefile
+++ b/Makefile
@@ -39,6 +39,10 @@
 	source ./venv-xos/bin/activate ; set -u ;\
 	xos-migrate --xos-dir . -s core --check
 
+create-migrations: venv-xos
+	source ./venv-xos/bin/activate ; set -u ;\
+        xos-migrate --xos-dir . -s core -v
+
 core-xproto-test: venv-xos
 	source ./venv-xos/bin/activate ; set -u ;\
 	xosgenx xos/core/models/core.xproto --lint --strict