REIVEW: [NX-518] Orient database manager

This PR addresses the following issues:

https://issues.sonatype.org/browse/NX-518
https://issues.sonatype.org/browse/NX-519
https://issues.sonatype.org/browse/NX-542
if the intent is to have a "last known good export" from which the db can be re-constructed, then i don't see why it makes sense to remove it. what if the db gets borked again? but again, i'm unclear on who is responsible for creating these..maybe that same party should be responsible for cleaning them up?