Interfaces implemented:
/application/interfaces/User.php :  ifUser
/application/interfaces/Hash.php : ifHash

Fixed methods:
/application/controllers/User.php :
find_hash
find_user
Now these methods will return ONLY bool.

Added methods:
/application/controllers/User.php :
get_user
get_hash
these methods will return ONLY array

To do:
/application/models/User_model.php:
line 81