Fix
issue #570 (GoBack() slot connected twice)
Clear nickname in case of collision so client could try again. Should help with
issue #550 if not fix it.
Rooms list/chat splitter from
issue #612
Add gstFrozen state to mines/gears in range on frozen land creation, and set the mines to dud state. gstFrozen does nothing yet. Visually or otherwise.
yes. forgot this one too