[PATCH ZBX-1367] function zbx_date2age is not localized

[alixen]

Hi,

Durations are not localized in graphs.
Time units (y, m, d, h, m, s) are always displayed in english.

I have opened bug ZBX-1367 and joined patches that correct it
See : https://support.zabbix.com/browse/ZBX-1367

Regards,
Alixen