Timing cache works for hello world test.

Still need
1) detailed CPU (blocking ability in cache)
1a) Multiple outstanding requests (need to keep track of times for events)
2)Multi-level support
3)MP coherece support
4)LL/SC support
5)Functional path needs to be correctly implemented (temporarily works without multiple outstanding requests (simple cpu))

src/cpu/simple/timing.cc:
    Temp hack because timing cpu doesn't export ports properly so single I/D cache communicates only through the Icache port.
src/mem/cache/base_cache.cc:
    Handle marking MSHR's in service
    Add support for getting CSHR's
src/mem/cache/base_cache.hh:
    Make these functions visible at the base cache level
src/mem/cache/cache.hh:
    make the functions virtual
src/mem/cache/cache_impl.hh:
    Rename the function to make sense
src/mem/packet.hh:
    Accidentally clearing the needsResponse field when sending a response back.

--HG--
extra : convert_revision : 2325d4e0b77e470fa9da91490317dc8ed88b17e2

src/mem/cache/base_cache.hh

@@ -153,6 +153,17 @@ class BaseCache : public MemObject
         fatal("No implementation");
     }
 
+    virtual Packet *getCoherencePacket()
+    {
+        fatal("No implementation");
+    }
+
+    virtual void sendResult(Packet* &pkt, bool success)
+    {
+
+        fatal("No implementation");
+    }
+
     /**
      * Bit vector of the blocking reasons for the access path.
      * @sa #BlockedCause