Fix gamelist refresh on leaving game

Game list update was skipped if the game list wasn't visible.  Fix up a
couple of cases when switching back to the game list the update was
called in the wrong order.
Add some error handlers for leaving games.

Trying to leave an invalid game always succeeds.  Trying to get game
info about an invalid game (that you think you're still in) makes you
leave it.
Fix logout error handler

Looks like a missed edit.
Merge pull request #43 from uecasm/leavegame

Improvements to error handlers