Refactor KRPCAddon so that the server logic is contained in KRPCServer, plus minor refactoring to Server namespace
 - Improve non-generic versions of IServer and IClient
 - Add non-generic events
 - Remove UI code dependencies on Server.Net namespace
Add OnServerStarted, OnServerStopped and OnClientActivity events
Update toolbar icon switching to use events
Add missing file
Replace spin lock with an AutoResetEvent
Do server update in FixedUpdate
Move UI event handler into UI code
Handle errors when parseing IP address from config
Fix warning
Move network info code into utils class
Add test
Add ServerException, and check for socket errors in TCPServer
Display server errors in UI
Add documentation to interfaces
Merge branch 'feature/server-minor-refactoring'