Specify "MasterEvent" property in events, triggered from Temp Handler

In-Portal uses kTempTablesHandler class to manage whole process of safe record editing within temporary tables.
During whole process several events, like "OnBeforeCopyToLive", "OnAfterCopyToTemp" and such are triggered.

However $event object available in them doesn't have $event->MasterEvent attribute populated with original event with caused temp handler processed action to happen.