Fixed broken SVN Commit dialog.
Summary:
SVN commit dialog was showing incorrectly because QDialogBox buttons were not attached to the dialog window.
Also fixing memory leak on QDialogButtonBox creating.
Reviewers: Dolphin, elvisangelaccio, meven, ngraham
Reviewed By: Dolphin, elvisangelaccio, meven, ngraham
Subscribers: ngraham, meven
Differential Revision: https://phabricator.kde.org/D26115