Don't use .fit() for avatar image in FriendList

Using fit here may cause wrong aspect ratio (if the avatar image is not
quadratic).
Fix Friendlist item layout mess-up with large text

- list items are now resized if neccessary
- moved username into the LinearLayout that contains the last online/
  friends since dates
- profileImg is centered vertically if list item is resized
- use layout_weight for center LinearLayout to prevent the status bar
  from floating out of the view
Merge pull request #166 from d-sko/friendlist_fix

Friendlist fixes