Add the sort arrows to the grid view instead of "ST"

[tacman]

I'd be nice to see the sort arrows with the column name when sort is active.

Idea: put a dimmed up/down sort arrow by the columns that are sortable. When a sort is active, un-dim the arrow. Here's an example from datatables, where it's easy to see that the I column is sorted, and the O column is sortable.