Changes

tsk8 Adds get and find functions in UserService
The get and find function was added in the UserService class to complete
the ejb functionality. The login parameters, such as class id, and
password were added to the user class. Obviously, modifying all the
classes that refer to the user. The id parameter was added in the player
class, such as id, in order to allow several players with the same nick
in the system. Obviously, all the classes that refer to the player were
modified. The id parameter was added in the competition class, such as
id, in order to allow several competitions with the same name in the
system. Obviously, all classes that refer to competition are modified.