Core: auto alias (#1022)

* Test: check that default templates can be parsed into Option objects

Options.py

@@ -26,13 +26,18 @@ class AssembleOptions(abc.ABCMeta):
 
         attrs["name_lookup"].update({option_id: name for name, option_id in new_options.items()})
         options.update(new_options)
-
         # apply aliases, without name_lookup
         aliases = {name[6:].lower(): option_id for name, option_id in attrs.items() if
                    name.startswith("alias_")}
 
         assert "random" not in aliases, "Choice option 'random' cannot be manually assigned."
 
+        # auto-alias Off and On being parsed as True and False
+        if "off" in options:
+            options["false"] = options["off"]
+        if "on" in options:
+            options["true"] = options["on"]
+
         options.update(aliases)
 
         # auto-validate schema on __init__