Updated indentation in server according to Android code style

Forgotten file.
See http://source.android.com/source/code-style.html#use-spaces-for-indentation
One difference - lines doesn't exceed 80 columns.
Implemented users logging in

Very basic functionality. User is not checked for existance so
anybody can connect.

Also server is asked for contact list after client logins. Again
very simple contact list is never updated then.