[TACHYON-220] WIP Comments describing issues and possible solutions 

Some initial comments to help improve the performance of master info. From what I gather there is locking on stack local objects that are never really put back into the map. I would appreciate suggestions before implementing it, hence the WIP tag.
I see the Gotcha now, in my example I was using native types, so you are correct,  with objects it changes. Point taken.

 HashMap<String , String > s= new HashMap();
    s.put("Hello","World");
    String p=s.get("Hello");
    p="Bye";
    System.err.println(s.get("Hello"));

produces hello world 

    map.put("foo", new Foo("foo"));
    Foo foo = map.get("foo");
    foo.name="bob";
    System.err.println(map.get("foo").name);

produces bob