Tgtd policy

[Matthew Ife]

Tgtd is a iscsi target daemon for linux. Its eventually going to also do
FCoE but currently doesnt.

Heres my policy for it. It needs some cleanup and i've not tested it
with proper fixed disk devices. I assume the kernel actually does most
of the read/write of the devices itself so the block device access i've
given the daemon is minimal.

Any feedback appreciated.