curl: Add native libcurl windows library

Add a native libcurl library. The version of the libcurl is 7.29.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
windows: Change winsock inclusion

Changes winsock inclusion into winsock.h as bug2issue is linking to the
winsock32.lib.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>