Add constants for different type of options for selecting the group of users.
Modify the getFriendList method to return the list of friends depending on the option given.
Implement the choosing of friends corresponding to All/Online/Offline/Blocked catergory they are in.
Fix errors that result from the changes.
Merge branch 'work' of https://github.com/Corly/Antox into Corly-work
Merge branch 'Corly-work'