Old format is still available as a fallback.

It's a hack. More proper solution to come.

Done-with: hjk

ModelNode::addChildNode() crashed

I added more checks for undefined - there should be no warnings left

increasing the size of the property editor a bit

showing up in Qt.

Yeah, now it looks as bad as the native completion widget :)
Reported by Nigel.

The smart backspace handling required a preceeding
non empty text block. In this case, the fix introduces
a standard backspace (deletePreviousCharacter).

Reviewed-by: dt

Streamline code, avoid functions and container.end() invocations,
introduce private, reduce #ifdefs, clarify code and add
comments about usage on various platforms.
Implement QFileIconProvider interface, making it usable for file system
models. Use in FolderNavigationWidget. On this occasion, add checkable
"Synchronize" action to FolderNavigationWidget.
Task-number: QTCREATORBUG-62