Add a ping command.
Add a ping command.

It's just too needed.

u-root/u-root,hugelgupf/u-root,rminnich/u-root,hugelgupf/u-root,u-root/u-root,hugelgupf/u-root,u-root/u-root,rminnich/u-root,rminnich/u-root,GanShun/u-root,GanShun/u-root,hugelgupf/u-root,rminnich/u-root,GanShun/u-root