REG[4.5->4.6]: Imageformat plugin for Windows .ico files can no longer read file

• Ensure .ico image plugin is installed in 4.5/4.6
• Open Designer
• Start form with a push button
• In the property editor, choose "Choose file" from drop-down of "icon" property tool menu
• Select the attached file
• Note the error: "The file '.../connect.ico' could not be read: Unable to read image data"
• Check with 4.5: The image is displayed on Linux/Windows without problems.

Alternatively, try the imageviewer example from (examples/widgets/imageviewer).

Subtask of http://bugreports.qt.nokia.com/browse/QTCREATORBUG-627