Get Port stuff working with full-system scripts.

Key was adding support for cloning port references (trickier than it sounds).
Got rid of class/instance thing and go back to instance cloning...
still don't allow changing SimObject parameters/children after a
class (instance) has been subclassed or instantiated (or cloned), which
should avoid bizarre unintended behavior.

configs/test/fs.py:
    Add ".port" to busses to get a port reference.
    Get rid of commented-out code.
src/python/m5/__init__.py:
    resolveSimObject should call getCCObject() instead of createCCObject()
    to avoid cycles in recursively creating objects.
src/python/m5/config.py:
    Get rid of class/instance thing and go back to instance cloning.
    Deep copy has to happen only on instance cloning then (and not on subclassing).
    Add getCCObject() method to force creation of C++ SimObject without
    recursively creating its children.
    Add support for cloning port references (trickier than it sounds).
    Also clean up some very obsolete comments.
src/python/m5/objects/Bridge.py:
src/python/m5/objects/Device.py:
    Add ports.

--HG--
extra : convert_revision : 4816d05ead0de520748aace06dbd1911a33f0af8

src/python/m5/objects/Bridge.py

@@ -3,6 +3,8 @@ from MemObject import MemObject
 
 class Bridge(MemObject):
     type = 'Bridge'
+    side_a = Port('Side A port')
+    side_b = Port('Side B port')
     queue_size_a = Param.Int(16, "The number of requests to buffer")
     queue_size_b = Param.Int(16, "The number of requests to buffer")
     delay = Param.Latency('0ns', "The latency of this bridge")