Issue #31 Add event description field

Events should be created with descriptions. Add a description textarea field to the
event form. Accept it as a parameter in the event controller. Add description to both json
builders.
Issue #31 Add maring below event heading
Issue #31 Give the event its id after create

When the event is created have the builder generate its id so that it
will be populated with the id it has on the server.
Merge branch 'event_page'