python: Move various utility classes into a new m5.util package so

they're all in the same place.  This also involves having just one
jobfile.py and moving it into the utils directory to avoid
duplication.  Lots of improvements to the utility as well.

--HG--
rename : src/python/m5/attrdict.py => src/python/m5/util/attrdict.py
rename : util/pbs/jobfile.py => src/python/m5/util/jobfile.py
rename : src/python/m5/util.py => src/python/m5/util/misc.py
rename : src/python/m5/multidict.py => src/python/m5/util/multidict.py
rename : util/stats/orderdict.py => src/python/m5/util/orderdict.py

src/python/m5/SimObject.py

@@ -32,7 +32,6 @@ import sys, types
 import proxy
 import m5
 from util import *
-from multidict import multidict
 
 # These utility functions have to come first because they're
 # referenced in params.py... otherwise they won't be defined when we