Zabbix

.......PS. [DEV-4334] added supervisor process, converted preprocessing and configuration syncers to threads manaed by supervisor

Merge in ZBX/zabbix from feature/DEV-4334-7.5 to master

* commit 'e8112fd2f24394dc3afd4a9195c6a34d6fbaa568': (120 commits)
  ........S. [DEV-4334] fixed double free
  .......PS. [DEV-4334] fixed includes
  .......PS. [DEV-4334] moved some of common supervisor unit initialization to 'prestart' function
  .......PS. [DEV-4334] improved server/proxy shutdown detection in supervisor components
  .......... [DEV-4334] fixed Zabbix proxy configuration syncer graceful shutdown during startup
  .......... [DEV-4334] fixed build without atomics
  .......... [DEV-4334] fixed includes
  .......P.. [DEV-4334] fixed proxy build without tls
  .......P.. [DEV-4334] fixed memory leak on shutdown
  .......PS. [DEV-4334] added freeing of cached compiled regular expression when exiting thread
  ........S. [DEV-4334] fixed worker clients not being retained by managers
  .......P.. [DEV-4334] fixed configuration syncer profiling
  .......PS. [DEV-4334] added process number validation when forwarding loglevel, profiling control messages with RTC notifications, added supervisor control by pid
  ........S. [DEV-4427] fixed database upgrade patch
  ........S. [DEV-4334] fixed include
  .......PS. [DEV-4334] added freeing of profiling vector on thread exit
  .......PS. [DEV-4334] added freeing of profiling vector on thread exit
  .......... [DEV-4334] fixed includes
  .......... [DEV-4334] fixed cmocka build
  .......PS. [DEV-4334] fixed typo
  ...