Enhancement request - Sortable columns in Mega Milestones table in User Milestones.

I don't know how easy it is to add column headers that facilitate a sort on the column in a table, but it would be quite a handy feature in a few places, but particularly in the Mega Milestones table as seen from User Milestones. All four numeric fields could be useful if sortable to help provide targets for people who like to chase thier stats. It would also provide a much more easy way of checking the numbers too, and make it easier for people to work out why they have some milestones, like MiRBs for example.