AtomicSimpleCPU with a cache now runs the hello world! test program.

AtomicSimpleCPU with a cache now runs the hello world! test program.
Need to clean up a bunch of flags/hacks in the code.  Then onto Timming mode.

Functional accesses also work properly, although not exactly how we wanted them.  I'll need to clean that up as well.

src/cpu/simple/atomic.cc:
    Atomic CPU needs to set thread context so stats work in cache.  Temporarily just use CPU=0 ThreadID=0
src/mem/cache/cache_impl.hh:
    Need to return success/failure properly still
    Physical memory object doesn't assert SATISFIED anymore, need to remove that flag
src/mem/cache/tags/lru.cc:
    Doesn't work if the REQ doesn't set it's ASID.  Temporary fix use 0 always

--HG--
extra : convert_revision : d06a39684af593db699b64df9a29f80c61d8d050