Added AppIcon and set LaunchImage

Added a bunch of icons for the AppIcon and set the LaunchImage to
Storyboard.storyboard in Xcode.
Created a new archive and fixed messages

… fixed the messages controller. Originally, if there was no
conversation between two users, the user could message the other and
create a new conversation. However, there was also a check that if
there were MORE than 0 messages within a conversation, then continue
the conversation. However, since the message/ conversation was new, the
conversation was never actually captured to continue the conversation
(after creating a new one).
Updates all the files to latest Swift syntax @thedlu