Zabbix

...G...PS. [ZBXNEXT-5543] added compression support for Zabbix agent 2

* commit 'c4285de0aeeaea16c1ace9bb5811b92b3d471dfd':
  .......... [ZBXNEXT-5543] added ChangeLog file
  ...G...... [DEV-1162] remove unused function
  ...G...... [DEV-1162] send compressed response for compressed history values received from agent or sender
  ...G...... [DEV-1162] compressing server answer for compressed agent request
  ...G...... [DEV-1162] revert debug changes
  ...G...... [DEV-1162] fixed works with flags
  ...G...... [DEV-1162] agent2 compression support

(cherry picked from commit 7dbbf71d1165c4965fc196eea24e8e44fee68f22)