Simple Network Time (NTP) Protocol Client

http://en.wikipedia.org/wiki/Network_Time_Protocol

우리나라 타임서버 목록은 ...
1. NTP Primary Time Server(Stratum 1  Server)
   - time.kriss.re.kr
   - time2.kriss.re.kr
   - time.bora.net
   - ntp.kornet.net
   - ntp.postech.ac.kr
   - ...
2. NTP Secondary Time Server(Stratum 2 Server)
   - ntp.ewha.net
   - ticktock.ewha.net
   - time.bora.net
   - ...

SNTPClient.cs