Fix hlint warnings.

Just one this time.
Add some feedback when a game is being launched to the interface.

Previously, if the Dwarf Fortress was not running, the interface would not give
any kind of feedback that the Dwarf Fortress screen is (hopefully) going to
appear in a few seconds. Now we show a small "starting up..." text to let the
user know at least something is happening.
Tell the players if the game is gone in the web interface.

Before, there was no indication the game had crashed/shut down other than the
screen not moving. Now you get a wonderful red and bright message.