Icon for owners, 2 more icons, autoimpact on stocks

The icon who shows who owns wich stock shows up att he stocks a player
buys and disapear when the player sells them all. Added 2 more icons to
shoose as a game character, just temporarly images. A button is added to
the MainWindow which randomly changes stocks between 0-20% up or down.
Simulated movement of characters randombly to impact the process of the
stocks.