Allow proxies to refer to proxies in config files.

python/m5/config.py:
    Allow proxies to refer to other proxies and resolve by recurseivly calling unproxy().
    Not sure this works completely (since I don't have any examples to test it on)
    but it doesn't seem to break any existing config scripts.

--HG--
extra : convert_revision : d7fc272d0777d85f89104dfb5d1c5e4d8ddd6d6f

python/m5/config.py

@@ -197,12 +197,13 @@ class Proxy(object):
                 raise AttributeError, \
                       'Parent of %s type %s not found at path %s' \
                       % (base.name, ptype, self._path)
-            found, done = obj.find(ptype, self._path)
-            if isinstance(found, Proxy):
-                done = False
+            result, done = obj.find(ptype, self._path)
             obj = obj.parent
 
-        return self._mulcheck(found)
+        if isinstance(result, Proxy):
+            result = result.unproxy(obj, ptype)
+
+        return self._mulcheck(result)
 
     def getindex(obj, index):
         if index == None: