add usb_reset

Hi

Sometimes, openni2 driver is not able to open or connect to device and we have to physically re-connect the USB cable to reset usb status, This program (usb_reset) is do similar effect with software.

if you know the usb device path using `lsusb` command, then you can try
```
rosrun openni2_camera usb_reset /dev/bus/usb/002/017
```

Cc: @garaemon