message: Add cache for vlist
  Add membets and funcions used for cache of vlist
diff: #include "Util.h"
  #include "Bstr.h"
  +#include "ClassForVlistCache.h"
  //NOTICE: not keep long list in memory, read each time
  //but when can you free the long list(kvstore should release it after parsing)
  @@ -74,7 +75,8 @@ private:
  //NOTICE: according to the summary result, 90% value lists are just below 100 bytes
  //<10%: 5000000~100M bytes
  FILE* valfp;
  -
  + // cache for vlist.
  + Longlist_inMem* longlist;
  //NOTICE: freemem's type is long long here, due to large memory in server.
  //However, needmem in handler() and request() is ok to be int/unsigned.
  //Because the bstr' size is controlled, so is the node.
  @@ -99,6 +101,7 @@ public:
  static bool isLongList(unsigned _len);
  static bool listNeedDelete(unsigned _len);
  + void AddIntoCache(unsigned _key, char*& _str, unsigned _len);
  };
  #endif
  