core: pass host/service obj ptr to logger on event.

refs #4754
Merge branch 'next' into feature/logentry-objid-4754
idoutils: add object_id to logentries (only populated on host/service events)

refs #4754
Merge branch 'next' into feature/logentry-objid-4754
change defaults to NULL

refs #4754
log states also get objects

refs #4754
change function prototypes

refs #4754
only insert object_id if not zero (leaving nulls)

refs #4754
Merge branch 'next' into feature/logentry-objid-4754
update Changelog

refs #4754
update docbook ptr