Improve auto-width of playlist columns behaviour

[happyuser]

Improve auto-width of playlist columns behavior:

Make only the Name column be automatically changed when the whole playlist's width is changed.

Index and Length columns should not be changing when the whole playlist width is changed because they have almost fixed data like "000" and "00:00:00" with almost the same width. These columns' width should be changeable by user but only manually not automatically with playlist width change.
It will be more convenient .

[csehszlovakze]