- add api.owner.get() to get default owner for a context + tests

- slave: get length for a specified slave and test
- add test for deref objects and default_multi
- add issubmulti, getdefault, getdefaultmulti
- start metaconfig support in api

tiramisu/setting.py

@@ -369,7 +369,7 @@ class Settings(object):
             return Property(self, properties, opt, path)
         return properties
 
-    def get_global_properties(self):
+    def get_context_properties(self):
         return self._getproperties()
 
     def __setitem__(self, opt, value):  # pragma: optional cover