Modified Fire Function
-Created new CanFire function which checks how long has passed since the last fire and if that time is greater than rate of fire, then it can fire again.
Changed menu strucutre
-Created new Menu class to handle drawing a menu and checking all input in that menu
-Created MenuButton class.  Extension of GameButton class that includes the use of an Action
-Created TextField class.  Used in menus for drawing the body text
-Makes the Game1 class responsible for determining the responsibility of each menu and defining how to transition from one game to another.
-This is one of many steps to make the Game1 class an overall manager of many game types and menus.  Helps to split up code and create a more re-usable system.
-Minor comment and game balancing changes