D17617: Display error instead of silently failing when asked to create folder that already exists

[Nathaniel Graham]

ngraham edited the test plan for this revision.

REPOSITORY
  R241 KIO

REVISION DETAIL
  https://phabricator.kde.org/D17617

To: ngraham, #dolphin
Cc: kde-frameworks-devel, michaelh, ngraham, bruns