CHANGES: snmpd: Add a missing function declaration
CHANGES: snmpd: Remove some unused includes
CHANGES: snmpd: Use 0 for the ignored numvars argument to netsnmp_register_mib

The numvars argument of netsnmp_register_mib is ignored if the var
argument is NULL. In order to unify this use of it with all other ones,
change it from 1 to 0
snmpnetstat: fix statistics for ipv6
CHANGES: snmplib: Avoid failure to trigger sign extension due to overlong types

In asn_realloc_rbuild_signed_int64 the algorithm assumes that shifting
values greater than 0x7fffffff right is an arithmetic shift that will
shift in 1's. On hosts where long is more than 32 bits the use of long
for 'low' and 'high' makes this assumption false.

Thanks to rkj@softhome.net for reporting this issue.