Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Adds the bsnmp module to export the temperature data from lm75 sensors on
the system.

Together with lm75(4) this module allows easy temperature monitoring over
SNMP, specially for embedded systems.

Manual page reviewed by: brueffer (D128)