[Mesa-dev] Use hwdb in loader

[Kristian Høgsberg]

This series fixes a few problems in the v2 udev hwdb patch (it broke on Kens
recent #ifdef PRELIMINARY addition) and then cleans up the loader logic a 
bit with the goal of making the loader use modalias strings to find 
drivers.  modalias strings are of the form

  <bus>:<device identifier>

and allows the loader to look up a driver for any device that the linux
kernel supports regardless of the bus it's on.

Kristian