Removed redundant field.

Also fixed a bug where comment creation was missing event_id.
More translations. Removed some unused actions.
Editing events.
Layout improvements.
Users can be admins. Admins see list of users.
Event was not saving the owner.
Event date in human-readable format.
Event with location and description.
Using PostgreSQL.
Fix to migration.
Precompiling assets to make CSS appear in heroku.
Canceling guests/contributions removes them. Contribution requires type.
Moved creation of items to outside of main page.
Comments sorting by date DESC. Dates in Portuguese offset.
Sorting contributions table.
Removed pre-compiled assets.

It was messing up development. Will need to figure out a better way
to fix the problem with heroku not displaying assets.
Contribution types: CRUD.

Also added some i18n under events.
Events sorted by date, and showing date on hover.
Events in the future are highlighted.
Editing contributions.