Bug Fixes in KDE Base
- Yet more createWindow related changes. Guess spoke too soon on previous commit.
This implementation is a robust generic fix that handles all window creation
requests from the browsing engine, i.e. QWebPage::createWindow.
Besides dealing with previous bugs such as 253708 and 258367 more appropriately,
it also prevents the duplicate creation of a new window if another one with the
same name already exists.