Network clock using 7 segment. add SHT11

Dependencies:   SHTx SNTPClient WIZnetInterface mbed

Revision:
0:179f2315915f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SNTPClient.lib	Tue Apr 05 11:50:51 2016 +0000
@@ -0,0 +1,1 @@
+http://developer.mbed.org/users/xeon011/code/SNTPClient/#137fc24033c4