D11993: Tweak column widths in tree view of file open/save dialogs

[Nathaniel Graham]

ngraham added a task: T8552: Polish Open/Save dialogs.

REPOSITORY
  R241 KIO

REVISION DETAIL
  https://phabricator.kde.org/D11993

To: sharvey, ngraham, dfaure, #frameworks, broulik
Cc: #dolphin, cfeck, fabiank, broulik, michaelh, bruns