The TIU activity is still messed up. But I've fixed a lot of stuff.

Fixes:
- No crash when you back out of the main activity and re-enter (Ian
showed me we needed to create a new activity for parse initialization to
fix this
- Bunch of other stuff involving the Leave/Join button

Problems:
- If you have old events, uninstall the app and don’t delete those
events… when you create one… and click on it… it will not ask you to
leave, it’ll just stick with a disabled join button. 
- If you DON'T have old events and you're starting completely fresh, you
can create an event. It joins you. You can click it and leave it. Then
you can click it and join it.. but when you click it again it stays as
join and doesn't give you the option to leave. MESSED!