Corrected amount of info in INFO level logs to contain ID of entities
only.
Added missing exceptions to generateMatches(League league) method.
Added MatchServiceImpl logging
Added logging to PrincipalServiceImpl
Renamed findUserByUser(User user) to findPrincipalByUser(User user) (wtf
=D )
Fixed amount of logged info in SportServiceImpl
Fixed amount of info logged in UserServiceImpl