for a single device.
Add a new function to the blkid library, blkid_probe_all_new().
Optimize blkid_find_dev_with_tag() so that extraneous device validation are
skipped. (Makes a difference for system with a large number of disks).
consistently when the blkid cache file is explicitly set
to /dev/null. (Addresses Debian Bug #292425)
Also expose blkid_verify() as a public function to the blkid library.