Removed old comment, LAPPS-70
Search for tags in getAllApps, LAPPS-70
Provides unique search result for users, LAPPS-69
Override equals method for App and User, LAPPS-69, LAPPS-70
SortBy for getAllApps, Comparatoren, LAPPS-70
SortBy for getAllUsers, Comparatoren, LAPPS-69
Added comments, changed User.compareTo field id, LAPPS-69, LAPPS-70