libusb.c: consolidate USB-related addvar() calls
Remove redundant usb_set_altinterface(), unless user requests it

Adds flag/value to USB driver options.

Closes networkupstools/nut#138
nut-usbinfo: ignore *.orig files
drivers : fix possible memory leak.

In arguments parsing, if user option is passed.
drivers : add Liebert GXT3 device.
Merge branch 'issue_138_altinterface_value'

Removing the usb_set_altinterface() call seems to be a net positive, but there
is a new `usb_set_altinterface` driver option to restore the old behavior.
missing -lm in drivers/Makefile.am

Both bcmxcp and bcmxcp_usb use ldexp(), so both need `-lm`.

http://news.gmane.org/find-root.php?message_id=544515BA.4060804%40niksoggia.it
docs: docinfo.xml is now auto-generated
riello_ser: enhanced handling error codes (0.03)
riello_usb: timeouts and error handling (0.03)

Small changes in riello_usb.c that solved some problem with managing
transmission errors between the Raspberry Pi and Riello ups (thanks to Fredrik
Öberg): introducing timeout in reading ups data in cypress_command; enhanced
handling error codes

http://news.gmane.org/find-root.php?message_id=f5294e5579574bcbaf5cdd95523e0b68%40AM3PR07MB289.eurprd07.prod.outlook.com
riello_usb: explicitly claim USB interface

Reference: http://news.gmane.org/find-root.php?message_id=7731ed2f98014b8a90e695a06d077970%40AM3PR07MB289.eurprd07.prod.outlook.com

and https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=738122
HCL: Rucelf UPOII-3000-96-EL supported by blazer_ser

Manufacturer: http://www.rucelf.ua/en/catalog/upoii-3000-96-el/

Closes: https://github.com/networkupstools/nut/issues/165
Merge branch 'Liebert_GXT3_0008'

Reference: http://news.gmane.org/find-root.php?message_id=7056332.1066111.1412937856080.JavaMail.www%40wsfrf1124
usbhid-ups: comments describing Belkin/Liebert/Phoenixtec situation

Follow-up to issue #159.
upower: Update Belkin and Liebert rules

Follow-up to issue #159.
Update VMware ESXi package link (from René Garcia)
Store the git start point as a variable

For ChangeLog, we now store the git start point (older reference) in a
separate variable, to make the process more clear
openups-hid: add USB ProductID d005 for OpenUPS2
openups-hid: const and float/double fixups (0.2)
openups-hid: remove a const; this will require more thought

The USB matching routines should have their parameters marked as "const" to
indicate that they do not modify the matching tables, but that will require
more invasive changes. Roll this back for now.