[PATCH] udevinfo - now a real program :)

[PATCH] udevinfo - now a real program :)

I want to make udevinfo the standard query interface, so all the user
features of the main udev are copied in here. It is now capable to:

  o query the database for a given value
  o dump the whole database
  o extract all possible device attributes for a sysfs_device

In addition to the known options of udev it supports the query for the
mode of the device node, and it includes the mode in the database dump:

  udevinfo -d
  P: /class/video4linux/video0
  N: video/webcam0
  M: 0666
  S: camera0 kamera0
  O: 500
  G: 500

It is also a bit more friendly with the pathnames specified for devices or nodes.
We remove the absolute path or add it if neccessary:

  udevinfo -q mode -n video/webcam0
  udevinfo -q mode -n /udev/video/webcam0
  0666

  udevinfo -q mode -p /sys/class/video4linux/video0
  udevinfo -q mode -p /class/video4linux/video0
  udevinfo -q mode -p class/video4linux/video0
  0666