Disable drives

[Joshua Hesketh]

The purpose of the "drives" module is to control which disks the user can access. In an exam the most likely scenario is that they are only allowed access to the thumb drive with the questions and answers. Internal hard drives, SD/MMC, CD/DVD etc will need to be disabled.

Disable drives based off type, label or uuid. Basic pseudo code:
# Loop each drive
# Check drive type is NOT in blacklist OR IS in whitelist
# Check drive label is NOT in blacklist OR IS in whitelist
# Check drive UUID is NOT in blacklist OR IS in whitelist

This should allow three different level of settings. The Label and UUID should be easy to implement. The most useful one, type, is also the hardest. We need to be able to have a config like:
disallow_types: all # (cdrom, sd, thumb, hdd, etc)
allow_types: thumb # This will overwrite the disallow rule

[Joshua Hesketh (joshua.hesketh)]

Better psuedo code:
for each device:
  if in type_blacklist:
     block = true
  if in type_whitelist:
     block = false
.... repeat for label and uuid