Tidy up description and code formatting in usb plug-in

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
Add partition data to block plug-in and tidy blkid code

Collect /proc/partitions in the block plug-in where it belongs
(not in the cluster or file system plug-ins where it has hidden
in the past!).

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
Add new ATA/IDE plug-in

Separate the ATA and IDE code from the hardware god-object and
put them in a separate plug-in that is activated by the presence
of hdparm or smartmontools.

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>