python: Improve support for python calling back to C++ member functions.

Add support for declaring SimObjects to swig so their members can be wrapped.
Make sim_object.i only contain declarations for SimObject.
Create system.i to contain declarations for System.
Update python code to properly call the C++ given the new changes.

--HG--
extra : convert_revision : 82076ee69e8122d56e91b92d6767e356baae420a

src/python/m5/internal/__init__.py

@@ -30,6 +30,5 @@ import core
 import debug
 import event
 import random
-import sim_object
 import stats
 import trace