MythContext::IsConnectedToMaster(void) doesn't work reliably

[Paul]

You can't reliably use MythContext::IsConnectedToMaster?(void) to determine if you have a valid connection to the Master Server because it always returns true after a successful connection has been made even when the Master Server has gone away.

It means you can't use something like:

if (!gContext->IsConnectedToMaster())
    gContext->ConnectToMasterServer();

to make sure a connection is still alive.

Paul

[Paul]

Possible fix - deletes the server socket when the event socket is closed

[Isaac Richards]

(In [7180]) Patch from Paul to kill off the command socket if our event socket went away.

Fixes #274.