D23333: KDirOperator: Only enable "Create New" menu if the selected item is a directory

[Méven Car]

meven added a reviewer: Frameworks.

REPOSITORY
  R241 KIO

REVISION DETAIL
  https://phabricator.kde.org/D23333

To: daandemeyer, #frameworks
Cc: meven, kde-frameworks-devel, LeGast00n, GB_2, michaelh, ngraham, bruns