Race Pending Phase 2

Built in some of my RacePendingActivity work into the
UserSelectorFragment.  Now when you add a new friend and that friend
“accepts the race invitation” (for now by sending a join, username JSON
object from the pub nub interface), an asterisk will show up next to
their name in the Fragment.  This asterisk can later be changed to
change the image, bold the text, or whatever we want to use as a
designator that the friend has accepted the race invitation.

To dos:
- Add communication between the UserSelectorFragment and the Start
Button for enabling the button every time a new user accepts the
invitation.
- Clean up the Pubnub work so that it is repeated as little as possible
- Integrate the User data from login and the RaceId information from
the intent to populate the Me information instead of the fake
information I have supplied in the onCreate method on the fragment.
- Deal with error case of third user joining after second user and not
knowing the second user has joined (users should be sending pings for
presence when they receive a join message and a receiver should be
added for that action type)
…