Zabbix

.......PS. [ZBX-9666] add community (SNMPv2c) and context, security name (SNMPv3) to SNMP dynamic index cache

This helps eliminating situations when 2 SNMP agents have the same IP,
port and OID but differ by community/context and/or security name.

[svn merge ^/branches/2.4 -c r55534]