Add common-use columns

Improves the index page for attendees by adding several new columns and
keeping each column its own unique data type.
Add badge_type_with_ribbon

Adds a property for a future UI change where badge types will be
displayed in AnthroCon style.
Move phone number field

Moves the phone number field up to show before the EC phone number
fields.
Track attendees and groups with uuid

The Tracking function used to simply store the group or attendee name
which recording changes - this changes it so it stores the uuid to
guarantee unique entries. Also partially implements a created property
for attendees.
Add created and last_updated properties

Adds a way to retrieve tracking data by attendee instance, and uses it
with the created and last_updated properties for attendees. This
displays on their admin form.
Use fk_id instead of which

It turns out fk_id stores the actual id of the instance, so this
switches to using that instead of changing the data stored in Tracking.
Improve created and last_updated

Moves the get_tracking functions to MagModel so they're more useful.
Also adds filters to the result so they display in local time.
Merge pull request #821 from magfest/ui_changes

UI changes