Add basic proxy suport
commits from 702adf91f5bb6ba2146c678dcbcd3f8eed10a5df to cedc9ccd66401990e4443b2bc76b069ab0ca560c from https://github.com/hailocab/zabbix
Add basic history suport and ItemsUpdate
commits 24f02370ef8f4cb8a430b4e48b46fc688b48e1f9, 0d0dfd6af63a7d76b7ea4e4caea2f72ca34299a7 and b4df791263b5540e4416965a6b409cecd3e13ea1 from https://github.com/grooveshark/zabbix
Add basic support for SLA, events and triggers
(commits 52e74e0b68cccfc071220cedbc2828590d3872b1 and ab90715133b3371d6cfe6556c56a92f618fca3fe from https://github.com/ipartner/zabbix)
Add TriggerCreate
(changed commit 1adb6b69830615aa23363b6fe76a1069792a8a1c from https://github.com/hailocab/zabbix)
Add Zabbix version storing. Make compatible with 2.4
(minor changes in commits 340c5c13a8407367b8de6d7fe579fe10eefafb78, 45313506fb8ff3db3a43ce66742c68f7a9849510 and 9f98c4b26231ec20a80d44c6824d4fcd6514316b from https://github.com/sladewig/zabbix)