Merge pull request #13 from chenyong111/master

【修复】适配网络框架，添加有关时间操作头文件支持。

SConscript

@@ -4,6 +4,6 @@ cwd     = GetCurrentDir()
 src     = Glob('*.c')
 CPPPATH = [cwd]
 
-group = DefineGroup('WebClient', src, depend = ['RT_USING_LWIP','PKG_USING_WEBCLIENT'], CPPPATH = CPPPATH)
+group = DefineGroup('WebClient', src, depend = ['PKG_USING_WEBCLIENT'], CPPPATH = CPPPATH)
 
 Return('group')

webclient.c

@@ -15,6 +15,8 @@
 
 #include <string.h>
 
+#include <sys/time.h>
+
 #ifdef RT_USING_DFS_NET
 #include <netdb.h>
 #include <sys/socket.h>