NEXUS-7370: update EventSubscriberHost to use dynamic registration
NEXUS-7371: remove the automatic feature discovery in favour of a strict list of features to install
Remove unused test file
Move to OrientDB 2.0-M3
Revert "Move to OrientDB 2.0-M3" as it affects StagingManagerIT

This reverts commit b93e66f463fb0360db59a4b7331c7bb0e8dee8a6.
Merge remote-tracking branch 'origin/master' into NEXUS-7336-osecurity-step-3