Windows: Police Library IOCTLs

Ensure that the callers of the various library ioctls have
the correct identity or privs.  All this policing is done in
the fs (non unloadable) layer, and to ensure that the library
layer cannot receive these calls directly we forbid non
create Opens of the library control device.

Change-Id: I2342fe10047642082adfbd1cc6aaee09cc91b520
Reviewed-on: http://gerrit.openafs.org/8893
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>