start annotation-to-attribute storage migration step
don't use annotation storage for Location, Attendees and Contact
update test to check for behaviour-based marker interface
BBB for the old marker interfaces for Location, Attendees and Contact
Revert "BBB for the old marker interfaces for Location, Attendees and Contact"

This reverts commit 5f319091ab1c08b154ca01568144264baea94979.
make sure to actually include the upgrades for dx
added upgrade step to migrate the annotation storage from behavior fields
Added a test for the annotation to attribute storage migration
add a test that checks that already existing values don't get overwritten by the storage migration
Merge branch 'plone5' into remove-annotation-storage-95
nicer descriptions in the tests
Remove the 3 deprecated interfaces for the behaviors. They were only used in tests
In the upgrade step, if we modified content, we should actually throw the ObjectModified event
we can simplify the indexer for SearchableText. We don't need to apply the IEventSummary behavior, since
the data (text) is already provided by the EventAccessor
also move the EventSummary (text) from Annotation to Attribute storage
Merge branch 'master' into remove-annotation-storage-95
Use attribute storage instead of annotation storage in all Dexterity behaviors. Closes #136, #95, Refs #20.