Added a main menu and fixed som things. added explotions to and fixed the economy

src/ei/game/input/InGameKeyboardInput.java

@@ -1,5 +1,31 @@
 package ei.game.input;
 
-public class InGameKeyboardInput {
+import org.lwjgl.input.Keyboard;
+
+import ei.engine.LWJGLGameWindow;
+import ei.engine.input.KeyboardInput;
+import ei.engine.state.GameStateManager;
+
+public class InGameKeyboardInput extends KeyboardInput{
+
+	public InGameKeyboardInput() {
+		super("InGameKeyboardInput");
+	}
+
+	@Override
+	public void keyDown(int keycode) {
+		if (Keyboard.KEY_ESCAPE == keycode) {
+			if(GameStateManager.getInstance().getState("MenuState") != null){
+				GameStateManager.getInstance().setDeActive("InGameState");
+				GameStateManager.getInstance().setActive("MenuState");
+			}
+			else{
+				LWJGLGameWindow.exit();
+			}
+		}
+	}
+
+	@Override
+	public void keyUp(int keycode) {}
 
 }