Zabbix

........S. [ZBXNEXT-4108] added upgrade patch for existing events and problems

The upgrade patch will take care of identifying all the events and problem
records that indicated a problematic event and give those records a default
name.

For trigger events, the trigger description will be copied without any macro
expansion for both recovery and problem events.

For internal events, if the source is a trigger and the record indicate a problem
the default "cannot calculate trigger expression" error message will be stored
in the name field.
For internal events whose source is an item, the error message "cannot obtain
item value" will be saved. the same will happen for correspinding records in
the problem table.

The internal recovery events will not have a message stored (as per spec) and
also all the other event types will be left empty.

Discussed with Alexei Vladishev and Andris Zeila.