Log events in the module database as staging for the proper log
[event] Rudimentary event transfer from core staging collection to event log
Merge remote-tracking branch 'origin/core-media' into log-events
Improve event names and parameters to work better with the coming event infrastructure
[core] Fix media event parameters
Event pub/sub, and core backend module using that to generate media mirror events
Fix lint errors
[doc] Update docs on event processing
[event] More details on event.version
Merge remote-tracking branch 'origin/master' into log-events

Conflicts:
	doc/datamodel/event.md
	modules/core/lib/work.js
	modules/core/tests/test_media.js
[core] Fix unit tests, forgotten in merging
Merge pull request #43 from commonsmachinery/log-events

Basic event infrastructure