util_trayHiddenChange, which means an API change. In board, calculate
bottom of board based on bottom of tray when tray is hidden, and round
so that it's an exact multiple of cell height. In wince, take
advantage of the new parameter to fix the scrollbar so that very
constrained boards can be scrolled even when the tray is hidden.
message is length plus data. Use non-deprecated gtk select-like
function. With these changes can play full games through the relay on
gtk. Untested on ncurses but probably broken.