Added hashMap to PlayerInfo class. groups players into separate
ArrayLists by team name.
Adding the hashmap reduces the number of accesses to the DB because
we can reuse Player objects from the PlayerInfo Class instead of
creating 
them on the fly from the DB every time we want to view a Team's roster
or a Player from the original pInfo ArrayList.
This means we are less reliant on the network and the DB is more secure.
Overhead is more memory usage, but we would be using memory to access
the database too.
Adding the HashMap required overriding the equals() method in Player
class.
Eclipse has both an equals() and hashCode() generator built in. Used it.
Preserved original pInfo ArrayList for the players fragment
functionality.