move the conversion stuff that was in configs/kernel/Config.py into

the m5 package as convert.py
add a smartdict class which stores strings and can intelligently
interpret those string variables as several other types.
make the env dict use the smartdict class

python/m5/config.py:
    move a bunch of conversion functions into convert.py
    turn the env dict into a smartdict
    adapt the _CheckedInt stuff to deal with derived types
python/m5/objects/BaseCPU.mpy:
    env is now a smartdict and can properly convert to bool

--HG--
extra : convert_revision : 8abcd35a5ab14b82f280aea59020953869e33365

python/m5/objects/BaseCPU.mpy

@@ -4,7 +4,7 @@ simobj BaseCPU(SimObject):
     icache = Param.BaseMem(NULL, "L1 instruction cache object")
     dcache = Param.BaseMem(NULL, "L1 data cache object")
 
-    if Bool._convert(env.get('FULL_SYSTEM', 'False')):
+    if env.get('FULL_SYSTEM', 'False'):
         dtb = Param.AlphaDTB("Data TLB")
         itb = Param.AlphaITB("Instruction TLB")
         mem = Param.FunctionalMemory("memory")