Many many bugfix

- closes #43 
- Facebook URL field no longer manditory
- Google Calendar errors now render as a toast, instead of internal server erroring
- fix a few logical bugs for what events show up where
if the truthiness was not functioning properly, we should define [`__nonzero__`](https://docs.python.org/2/reference/datamodel.html#object.__nonzero__) on DateField and keep the rest of the clean