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/Device.py

@@ -4,6 +4,7 @@ from MemObject import MemObject
 class PioDevice(MemObject):
     type = 'PioDevice'
     abstract = True
+    pio = Port("Programmed I/O port")
     platform = Param.Platform(Parent.any, "Platform this device is part of")
     system = Param.System(Parent.any, "System this device is part of")
 
@@ -16,3 +17,4 @@ class BasicPioDevice(PioDevice):
 class DmaDevice(PioDevice):
     type = 'DmaDevice'
     abstract = True
+    dma = Port("DMA port")