Lobby peek mode.

[JSideris]

While playing the game, it should be possible to peek into the lobby. This will consist of some changes to how the lobby works.

• [x] Reconnect/disconnect buttons in lobby that appear after the game has started.
• [x] Play button disappears when game starts and reappears when game ends.
• [x] Reconnect/disconnect buttons appear after game starts, and disappear after game ends.
• [x] During peek mode, 3D ship previews animate.
• [x] After peek mode, return to game and respawn.
• [x] After peek mode, 3D ship preview should stop animating.
• [x] If disconnect during peek mode, restore menu.