Change track feed to a detailed table

[opatut]

The current track feed is a bit useless IMO. Most people don't name their tracks at all, so more information would be helpful to find the correct ones. Also, a tabular overview is probably way neater if you want to manage your own tracks. Let's change the "My tracks" page to a table instead.

• Track name
• Date recorded
• Date uploaded
• Length
• Duration
• Event count
• Status
• Visiblity

We can then also make this table sortable and searchable later, and if we're crazy, add the same table with tracks from all users for admins (which don't exist yet, but might some day).