Extend capabilities to 64-bits in preparation for some API changes.
The v1.0 virtio spec supports an extended size for guest/host
caps, but in practice 64-bits should last for a long time.
units(1): Add 'terse' support
	terse output is used when calling units from another script.
units: Support start of line comments with '#'
	Modern GNU units(1) supports comments anywhere with '#' but take the easy route for now and at least support start of line # comments.
units(1): Convert units.lib to use '#' instead of '/'.
	This allows us to run GNU units against our data files and compare the output.
	In addition, current units(1) does not support '/' as a comment at all.
Make options KPI more generic to allow it to be used for ports too,
not only for LUNs.
Create separate iSCSI port for every target (and potentially portal group).
Burry devid port method, which was a gross hack.

Instead allow ports to provide wanted target port and target IDs, and
LUNs provide wanted LUN IDs.  After that core Device ID VPD code only
had to link them together and add relative port and port group numbers.
Make REPORT TARGET PORT GROUPS to return something more sensible.

It requires more formalized LUN mapping to be exactly correct.
Add support for SCSI Ports VPD page.

Ports should also be filtered by LUN mapping.
Do not set port wwnn/wwpn directly, call ctl_port_set_wwns() to update
also target_devid/port_devid respectively.
Change ctl_add_initiator()/ctl_remove_initiator() KPI.

 - Store data in struct ctl_port to make it dynamic;
 - Make ctl_add_initiator() to choose free iid if caller passed < 0;
 - Remove unneeded now pool of iids from iSCSI.
Add support for READ FULL STATUS action of PERSISTENT RESERVE IN.

So far without initiator IDs.
Pass through iSCSI session ISID from LOGIN request to the CTL frontend.

ISID is an important part of initiator transport ID for iSCSI.
Add initiator transport IDs to READ FULL STATUS.

This is a hack. Should be rewritten somehow to store full IDs, but still
not consume 512KB of RAM per target.