Still missing prefetch and tags directories as well as cache builder.

Still missing prefetch and tags directories as well as cache builder.
Some implementation details were left blank still, need to fill them in.

src/SConscript:
    Reorder build to compile all files first
src/mem/cache/cache.hh:
src/mem/cache/cache_builder.cc:
src/mem/cache/cache_impl.hh:
src/mem/cache/coherence/coherence_protocol.cc:
src/mem/cache/coherence/uni_coherence.cc:
src/mem/cache/coherence/uni_coherence.hh:
src/mem/cache/miss/blocking_buffer.cc:
src/mem/cache/miss/miss_queue.cc:
src/mem/cache/miss/mshr.cc:
src/mem/cache/miss/mshr.hh:
src/mem/cache/miss/mshr_queue.cc:
    More changesets pulled, now compiles everything in /miss directory and in the root directory
src/mem/packet.hh:
    Add some more support, need to clean some of it out once everything is working

--HG--
extra : convert_revision : ba73676165810edf2c2effaf5fbad8397d6bd800