Show a loading indicator when waiting for data to load

[mrozbarry]

To know if the timer is loading:

• If the server indicates you are the timer owner, then loading is done (ie there is no data from any other user)
• ~If the server indicates you are not the timer owner, then...~
• Wait for mob list (may be empty)
• Wait for goal list (may be empty)
• Wait for timer setttings
• Loading is done

Having a hyperapp action that indicates that the timer is ready will give us a jumping-off point for other features in the future.