4.1.0: Improved snapshot event generation

Issues #42 and #43: Interface SnapshotEventProvider is deprecated, replaced by SnapshotEventGenerator. You can have multiple of those (one for each event type), which is useful if your application consists of several independent components with their separate events. Its main method also accepts a filtering parameter, which is filled from the Actuator event creation REST endpoint's body parameter – this supports e.g. creating snapshots for just recently modified objects.

How to migrate from 4.0.x

No changes are needed, the old SnapshotEventProvider interface is deprecated, but still supported (without filtering). It might be removed in a future major version (and will be mentioned again then). Replacing it by multiple SnapshotEvenGenerator beans should be straightforward.