[Banshee-List] Cleaning up TrackInfo?

[LCID Fire <lcid-fire gmx net>]

Hi.
Having to mess with the TrackInfo class I noticed a few things that
should perhaps be changed.

For start I'd say the members should be set to private - so they can be
changed through the properties only.

Also I think the properties itself should be set to virtual (at least
the getters) because this makes derived classes programming far cleaner.

Anybody disagrees?