[PATCH] udev - reverse user query options

[PATCH] udev - reverse user query options

Here we get the ability to query with the name of the node instead of
the device path. It uses a linear search over the whole database.

  kay@pim:~/src/udev.kay$ ./udev -q path -n video/webcam0
  /class/video4linux/video0

New version, with better function return codes for error handling.