Alarm_acceptSubmittedCredentialList: Activate "accept" transition.

This removes the need for limitting the number of documents to
process in a single transaction, thanks to searchAndActivate.
Also, handle catalog desynchronisation gracefuly in the event
of accept/accept race condition.
credential_interaction_workflow/scripts/Call_alarmActiveSense: Simplify.

Save one reindexation activity if alarm is not triggered.
Drop single-use locals.
Drop comment telling what the code already expresses.
CMFActivity: Set transaction user and note when executing Message.

In normal Zope usage, ZPublisher does this. TimerServer does not provide
publisher with a request (which would be irrelevant anyway), so
CMFActivity-managed transactions notes are empty.
Notes are useful to identify the cause of an object modification, so set
them in CMFActivity.