Attribute browser: remember custom column width settings

[RIFJo]

The UI should remember adjustments made to the column width in the "Object attribute info" tab. When selecting different groups or datasets, the UI resets to the default values. This means I have to manually resize the columns every time i select a different group/dataset, because the default widths are not useful for me.

An application-wide "keep user-selected sizes" solution would already be very useful. Individual per-object stored column-widths would be even nicer.

Using HDFView 3.1.3 on Windows x64