Merge branch 'V5-6-patches' into V5-7-patches

* V5-6-patches:
  CHANGES: snmplib: Rename memdup() into netsnmp_memdup()

Conflicts:
	agent/agent_trap.c
	agent/helpers/instance.c
	agent/helpers/old_api.c
	agent/mibgroup/disman/ping/pingCtlTable.c
	snmplib/snmp_api.c
	snmplib/snmpv3.c
	snmplib/transports/snmpTLSTCPDomain.c