Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Toss bogus mergeinfo.

MFC r235634

Fix and update battery status bits according to linux driver

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Import nvram2env, a device driver which imports various NVRAM-style
environments into the kernel environment.

The eventual aim is to replace these with specific drivers for
the various bootloaders (redboot, uboot, etc.) This however will
work for the time being until it can be properly addressed.

Submitted by: Aleksandr Rybalko <ray@dlink.ua>