FreeNAS Code

Reimplement user lock, password disable and their backend support.

Revert r7638, this requires more work.

- Read config file in chunks.
- Nuke the temporary file in the event that an error occurred.
- Simplify error handling code a little bit.

The uploaded config file is actually still in memory at the time that the upload is being performed. Thus, we can't trust the file attribute to point to something sane.

So, we're back to writing to a temp file, then reading it back.

let user be created with password _and_ disabled
1. create user with a password
2. lock it right after

Destroying volumes could leave the database in inconsistent state if there were ZVols currently in use.
Also handle the export of volumes without cascade works as expected

Wipe disks before using.

Fix for LDAP slider, possibly fixes ticket #723 as well.

fix code indent

restart istgt instead of try to reload