chain.h std::vector access improvements
chain.h std::vector access improvements

ColossusCoinXT/ColossusCoinXT,ColossusCoinXT/ColossusCoinXT,ColossusCoinXT/ColossusCoinXT,ColossusCoinXT/ColossusCoinXT,ColossusCoinXT/ColossusCoinXT,ColossusCoinXT/ColossusCoinXT