Zabbix

.......PS. [ZBXNEXT-2732] reworked discovery manager to use threads instead of processes

* commit 'bad9aef44b2c7ea8b05086bb8b6c67eac6c84834':
  ........S. [ZBXNEXT-2732] fixed warnings
  .......PS. [ZBXNEXT-2732] fixed initialization
  .......PS. [ZBXNEXT-2732] fixed memory leak
  .......PS. [ZBXNEXT-2732] fixed merge artifacts
  .D........ [ZBXNEXT-2732] added changelog
  .......PS. [ZBXNEXT-2732] fixed discovery results handling
  .......PS. [ZBXNEXT-2732] fixed about function pointer
  .......PS. [ZBXNEXT-2732] added casts
  .......PS. [ZBXNEXT-2732] changed to wake workers after all jobs added
  .......PS. [ZBXNEXT-2732] fixed host update
  .......PS. [ZBXNEXT-2732] fixed initialization
  .......PS. [ZBXNEXT-2732] fixed typo
  .......PS. [ZBXNEXT-2732] improved network discovery by adding concurrent checks