unbreak BEGEMOT-LM75-MIB.txt

The MIB has several bugs making it unusable. Fix it.

Reported-by: Eugene M. Zheganin <eugene@zhegan.in>
MFC-after: 2 weeks

Remove $FreeBSD$: two-line lua tag

Remove /^--\n--\s*\$FreeBSD\$.*$\n/

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)