Cleanup & Fixes for .NET 5 (#309)

- [X] Fixes several bugs
- [X] Updates more ordinal issues
- [X] Cleans up the code a bit
- [X] Turns classes static that should have been
- [X] Changes TcpServer.Instances to a HashSet

Bumps release version

Projects/Server/Configuration/ServerConfiguration.cs

@@ -244,7 +244,7 @@ namespace Server
                     break;
                 }
 
-                if (ipStr.IndexOf(':') == -1)
+                if (!ipStr.Contains(':', StringComparison.Ordinal))
                 {
                     ipStr += ":2593";
                 }