NetDB: Type changes (Gitlab #402)
So that DummyNDF may extend NDF again, not FNDF, which was wrong.
- Revert ctx.netDb() return type change
- Revert all DummyNetworkDatabaseFacade changes
- Add DummyNetworkDatabaseSegmentor
- FNDS/SNDF return type changes
- Add back casts of netDb() calls to FNDF where necessary
- Fix console NPE when using DummyNDF
- FNDS/SNDF cleanups
- Javadocs
Closes #402 (closed)