mehdi: finished MotorizedFireFighter class

src/main/java/controller/Controller.java

src/main/java/model/Extinguisher.java

src/main/java/model/Fire.java

src/main/java/model/FireFighter.java

src/main/java/model/ModelElement.java

src/main/java/model/MotorizedFireFighter.java

src/main/java/view/ViewElement.java