Fixes ZEN-7012. These changes were ported from the 4.2.x branch. event_summary triggers are now dropped and ZEP is responsible for their previous role. percona's pt-online-schema-change is now used when configured instead of mysql's optimize when optimizing event_summary. Reviewed by epowell.


git-svn-id: http://dev.zenoss.com/svnint/trunk/core@74323 f5df01ce-0320-0410-9ed9-ddcd13c732cc