RSM

.......... [ZBXNEXT-4358,ZBXNEXT-4359] merged from latest trunk; fixed conflicts in:

- create/src/schema.tmpl
- include/zbxjson.h
- include/zbxserver.h
- src/libs/zbxdbupgrade/dbupgrade_3050.c
- frontends/php/items.php
- frontends/php/include/classes/api/services/CDiscoveryRule.php
- frontends/php/include/classes/api/services/CItem.php
- frontends/php/include/classes/api/services/CItemGeneral.php
- frontends/php/include/classes/api/services/CItemPrototype.php
- frontends/php/include/defines.inc.php