Floating dock windows cannot be docked back

[Dmitry A. Kuminov]

This may be seen in any application using them such as qdesigner. Quite annoying. The only way to fix that is delete qdesigner settings to make it reset to all docked state. Normally, double clicking on the dock widget's title bar should dock it back.

Another problem is that floating dock widgets have a too thin border which also doesn't let them to be resized which is also wrong.

[Dmitry A. Kuminov]

This should be quite easy to fix and I want to see it in GA.

[Dmitry A. Kuminov]

The resizing and thin border problem is fixed in r497.

Docking the widget by double clicking the title bar doesn't work on OS/2 since we don't generate QEvent::NonClientAreaMouse* events for mouse events happening over the native frame window's controls such as the title bar, the sizing border etc. I will look into how difficult it can be to implement this.

[Dmitry A. Kuminov]

Delivering non-client area mouse events is implemented in r498.

Docking windows work as expected now: they can not only be double clicked on the title bar to switch from floated to docked but also can be dragged over the dock areas in the main window to dynamically place them to a desired dock (which is accompanied by some nice animation).