In a few minutes I will commit this to trunk. This feature allows the server and client to communicate through custom GUI interfaces without the need for protocol version changes. The first use case of this feature is Waypoints, which allow the server to send the client a list of visited locations, and allow the client to present those locations and notify the server of which location is chosen.

Here is a screenshot:


My cursor doesn't show up in the screenshot, but note that "Stoneglow" is displayed when I hover over the X near Stoneglow. This is data sent by the server to the client, and the client will send whichever button I click to the server. There are many other use cases for this, including "trade skill" interfaces.

I have not implemented the actual waypoint functionality. I only made this change now to fit it into 0.11.0 so we can start using it freely. I'll leave waypoint implementation to Dolfo since he's done most it already. Currently the only implementation I've done is a MM command "/waypoint" which shows this menu, and the server sends a message to the client with the player's selection.

I have documented this command in this wiki article.