plugins: Keep compatibility with old plugins location

dream/plugins/__init__.py

@@ -21,4 +21,9 @@ try:
     __import__('pkg_resources').declare_namespace(__name__)
 except ImportError:
     from pkgutil import extend_path
-    __path__ = extend_path(__path__, __name__)
\ No newline at end of file
+    __path__ = extend_path(__path__, __name__)
+
+# BBB Add compatibility names for plugins that moved.
+from DemandPlanning import AddDemandPlannerGenerator
+from DemandPlanning import DemandPlanningLine
+from DemandPlanning import PostProcessDemandPlanning