- created class Health.java; used to control a player's health
- Health.java now has a min/max range; constructor sets this range
- added member variable 'health' to Player.java; initialized with min value 0 and max value 5
- added override method 'getvalue' to Health.java'
- added method 'getHealth' to Player.java; used to get player's current health
- TobyBallClient.java now registers Health related classes with kryo
- TobyBallServer.java now registers Health related classes with kryo