Use the VersionDate to only load changed systems when calling GetAllSystems.
Use the VersionDate to only load changed systems when calling GetAllSystems.

This offers a huge performance boost at startup, after trilateration and
in various other places since loading all the systems can take seconds
whereas loading only the last few updates is nearly instantaneous

jgoode/EDDiscovery,mwerle/EDDiscovery,mwerle/EDDiscovery,jeoffman/EDDiscovery,jeoffman/EDDiscovery,jthorpe4/EDDiscovery,vendolis/EDDiscovery,vendolis/EDDiscovery,jgoode/EDDiscovery