Added null check for scan results to prevent a nullpointer-exception
Switched to non-blocking send to prevent blocking the connector thread on connection errors
ZContext usage and Zip inference
Addes SP for valid zip file length
Moved validation points to correct positions and inserted the recurring manifestation
Added null test
Added close() method to persistor interface.
Refactored ZippedFilePersistor
Refactored TransferThread
Forgot DummyPersistor
Merge branch 'feature/newNetworkSensors' into dev