Don't reconfigure the keyboard when the same client reconnects

[matt335672]

See #2656 for some background on this.

The RDP protocol assumes a single keyboard is used for input. When we connect, or reconnect, the details of this keyboard, including the layout are sent to the session as part of the client core data. This is then used to initialise the keyboard for the session.

We have to do initialise the keyboard, as a user may be reconnecting to a session from a different client. I can see that this would mess up a session where the user isn't connecting from a different client, and has made an effort to reconfigure their keyboard to match the session.

One possible way round this might be to save the client name used for the connection, and not reload the keyboard layout if the same client reconnects.

Comments anyone? Is there a better way to do this? Does this need to be a configurable option?