feature: add multitouch feature for touchscreen

With patch we can use two figure to room in and out using browser on PDA platform
which support multitouch

Signed-off-by: Royce Jiang <jiangxd@embedinfo.com>
Ethernet: add tether of ethernet

we can tether ethernet to wifi AP

Signed-off-by: Royce Jiang <jiangxd@embedinfo.com>
config: we do not config wallpaper, system will config it

Signed-off-by: Royce Jiang <jiangxd@embedinfo.com>