Added MiniMap Script

Same script from closed pull request #172. It renders icons on the overview map discussed in Issue #85. This script is currently not hooked up to the level scenes. It should be done programmatically, once the golfball, player and flag GameObjects have known names. Here are the inputs:

// Icons discussed in Issues #111, Issues #119, and Issue #110. Tested with the 512x512 TGA files.
Texture2D flagIcon;
Texture2D playerIcon;
Texture2D playerDirectionIcon;
Texture2D ballIcon;

float iconScale            // relative size of the icons on the MiniMap
Color playerColor       // main chosen color of player. Default color is red.
Transform player;        // GameObject of the client's cart
Transform flag;            // GameObject of the pin/hole.
Transform ball;            // GameObject of the client's ball
GameObject level;       // GameObject of the current level
Camera mapCamera;  // MiniMap camera