Game settings inputs for new game

[ogallagher]

When launching a new game, open a settings panel so the user can customize the game parameters:

• number of teams (current default = 2)
• player speed
• player size
• bullet speed
• bullet length/tracer
• frame limit (current default 1000)
• number of rounds (default = 4 rounds = 8 matches for two players)
• obstacle size

[ogallagher]

Of the above, I implemented a settings panel to change all except:

• bullet speed
• obstacle size