Start using AnonymousMethodExecutionContext instead of the normal function execution context with arguments

jedi/inference/value/__init__.py

@@ -1,6 +1,6 @@
 from jedi.inference.value.module import ModuleValue
 from jedi.inference.value.klass import ClassValue
 from jedi.inference.value.function import FunctionValue, \
-    MethodValue, FunctionExecutionContext
+    MethodValue
 from jedi.inference.value.instance import AnonymousInstance, BoundMethod, \
     CompiledInstance, AbstractInstanceValue, TreeInstance