Zabbix

.......PS. [ZBXNEXT-8567] added asynchronous SNMP pollers

Merge in ZBX/zabbix from feature/ZBXNEXT-8567-6.5 to master

* commit 'b528f4db10e81cfde22f6aa788fcd4bb4378dccd': (85 commits)
  .......PS. [ZBXNEXT-8567] initialize snmp library only if used
  ........S. [ZBXNEXT-8567] fixed build without ipv6
  .......PS. [ZBXNEXT-8567] fixed coding style, warnings
  .......PS. [ZBXNEXT-8567] perform probing only for v3 snmp interfaces
  .......PS. [ZBXNEXT-8567] replaced ZBX_ASYNC_TASK_READ_NEW task with input and post callback fd checking and recreating read/write events if necessary
  .......PS. [ZBXNEXT-8567] refactored snmp task entry/exit logging
  .......PS. [ZBXNEXT-8567] fixed warnings
  .D........ [ZBXNEXT-8567] added ChangeLog entry
  .......PS. [ZBXNEXT-8567] updated man pages and help
  .......PS. [ZBXNEXT-8567] fixed integration tests
  .......PS. [ZBXNEXT-8567] added mock tests
  .......PS. [ZBXNEXT-8567] fixed structure names
  .......PS. [ZBXNEXT-8567] fixed existing mock tests
  .......PS. [ZBXNEXT-8567] improved snmpv3 to be truly async
  .......PS. [ZBXNEXT-8567] improved snmpv3 to be truly async
  .......PS. [ZBXNEXT-8567] fixed build without snmpv3
  .......PS. [ZBXNEXT-8567] improved snmpv3 to be truly async
  .......PS. [ZBXNEXT-8567] make snmp bulkwalk async
  .......PS. [ZBXNEXT-8567] make snmp bulkwalk async
  .......PS. [ZBXNEXT-8567] make snmp bulkwalk async
  ...