更新至0.6.4版本(Update to version 0.6.4)

1. 777区块后难度调整时间改为1天(Difficulty adjustment protocol: 777-block
2. 移除警报(Remove Network Alert and Notification)
3. 修正Linux、Mac下编译问题(Fixed compliation error under Linux and Mac)
4. 减少最低交易费(Lower Min Transaction Fee)
5. 添加检查点(Add checkpoints)
6. 修正RPC检查(Fixed RPC Amount Check)
7. 更新部分翻译(Update some translation)
修正Linux编译问题(Fixed compliation error under Linux)
修正Linux 编译问题(Fixed compliation error under Linux)