Fix Client.IsConnected

[Baldstrom]

Client.IsConnected does not seem to be updating and events are not firing upon disconnect when the server software is closed gracefully.

[CaiB]

In my testing, this is what the client throws:

[ERR] Disconnected from server... Retrying...
[EXC] System.Net.Sockets.SocketException: The socket has been shut down
[EXC]   at System.Net.Sockets.Socket.Send (System.Byte[] buf) [0x00000] in <filename unknown>:0
[EXC]   at Scarlet.Communications.Client.SendTCPNow (Scarlet.Communications.Packet TCPPacket) [0x00000] in <filename unknown>:0