More cache fixes. Atomic coherence now works as well.

src/cpu/memtest/memtest.cc:
src/cpu/memtest/memtest.hh:
    Make Memtester able to test atomic as well
src/mem/bus.cc:
src/mem/bus.hh:
    Handle atomic snoops properly for cache->cache transfers
src/mem/cache/cache_impl.hh:
    Debug output.
    Clean up memleak in atomic mode.
    Set hitLatency.
    Still need to send back reasonable number for atomic return value.
src/mem/packet.cc:
    Add command strings for new commands
src/python/m5/objects/MemTest.py:
    Add param to test atomic memory.

--HG--
extra : convert_revision : 43f880e29215776167c16ea90793ebf8122c785b

src/python/m5/objects/MemTest.py

@@ -6,6 +6,7 @@ from m5 import build_env
 class MemTest(SimObject):
     type = 'MemTest'
     max_loads = Param.Counter("number of loads to execute")
+    atomic = Param.Bool(False, "Execute tester in atomic mode? (or timing)\n")
     memory_size = Param.Int(65536, "memory size")
     percent_dest_unaligned = Param.Percent(50,
         "percent of copy dest address that are unaligned")