This commit adds several event categories as data in event modules. The
purpose is to help people using the event application with some help
on event configuration done through event categories.
proposal.
Instead of posting a chatter message with the post data + storing a blob on the track
store directly the various data on the track object itself.
Post a message on the event to warn a new track has been created.
Updated the track website view. Instead of storing a blob, rebuild a correct
and editable track view on the website.
Thibault Delavallée