Refactor the context back into the ConfigurableInterface.

This also adds support for manually constructed configurables to
populate the config tree in the current context.

I'm still toying around with this though, I need to figure out
what to do with optional values and think the whole thing through
to make sure it's worthwhile.

volatility/framework/interfaces/plugins.py

@@ -26,18 +26,9 @@ class PluginInterface(configuration_interface.ConfigurableInterface, validity.Va
     """Class that defines the interface all Plugins must maintain"""
 
     def __init__(self, context, config_path):
-        super().__init__(config_path)
-        self._context = self._check_type(context, context_interface.ContextInterface)
+        super().__init__(context, config_path)
         # self.validate()
 
-    @property
-    def context(self):
-        return self._context
-
-    @property
-    def config(self):
-        return self._context.config.branch(self._config_path)
-
     @classmethod
     def get_requirements(cls):
         """Returns a list of Requirement objects for this plugin"""