Changes to embedded/Lab4

• 2015-09-07 16:20:47 UTC (SonicYang): Fix links
• 2012-10-16 05:34:21 UTC (jserv): Add assignment
• 2012-10-16 05:27:16 UTC (jserv): update mission of this lab
• 2012-10-16 05:18:23 UTC (jserv): Add 教學影片觀賞