nutdrv_qx: add Voltronic-QS subdriver (nutdrv_qx protocol=voltronic-qs)

A subdriver using a protocol, specific to UPSes manufactured by Voltronic Power, based on the 'mustek' one (i.e. 'QS').
nutdrv_qx: update manuals for new 'voltronic-qs' subdriver
nutdrv_qx: fix nutdrv_qx_blazer-common.{c,h} header comments
HCL: add Atlantis Land/Voltronic Power units supported by nutdrv_qx
snmp-ups: update and edit documentation
Merge branch 'zykh/nutdrv_qx_voltronic-qs'

New Voltronic-QS subdriver for nutdrv_qx.
blazer: fix man page references
[HCL] MicroDowell B.Box LP 500: genericups type 7

Closes networkupstools/nut#83

From @lxp:

UPS shutdown only works when on-battery and has a delay of about 1min until
execution (something between 50sec to 1min 30sec on mine).

References:
http://www.ezdirect.it/pdf/lp500.pdf
https://forums.gentoo.org/viewtopic-t-730172-start-0.html