When fully replacing existing document WikiStream instance output module should not generate delete event

Right now when not adding a new version to existing document the following event are generated:

• DocumentDeleted
• DocumentUpgraded

It should always be DocumentUpgraded event only even if we don't keep the previous document history.

This is important since DocumentDeleted to trigger some not desired cleanup (for example importing XWikiAllGroup and loosing all existing rights associated to that group).