Gui.data_rows is shared non-persistent state

[narc0tiq]

Being shared state, it really won't work for multiple forces (multiplayer same-force would be okay), and it looks like global.gui is also shared. Guess I ran a little too fast to the 0.2 tag.

Being non-persistent, things get interesting when joining a server game -- the client has a fresh copy of gui.* but the server doesn't (and has no reason to). This is actually what initially showed up as a desync on joining a paused game (I'm still not sure why joining an unpaused game doesn't do this).

This is pretty much critical and must be dealt with before the design gets any more complicated.