arrow and 'torn-off' tab while moving.

(Drag and drop between windows is supported only for windows within the same process,
which will be all windows opened from a GUI)

Some of this functionality could be moved to kdelibs / KTabBar for the benefit of other
applications.

BUG: 75653

Squashed commit of the following:

commit 1e5b628b74f4c7182b1aed159088f0d449bf6f1f
Author: Robert Knight <robertknight@gmail.com>
Date:   Tue Apr 15 11:32:04 2008 +0100

    Set drop indicator label to same size as pixmap.

commit 59ad9200465cfb76651ce81abd3ba20e2fdd3067
Author: Robert Knight <robertknight@gmail.com>
Date:   Tue Apr 15 11:14:41 2008 +0100

    Adjust drop indicator for north and south tabs.

commit 01ba5bca9457bc19156f5a87ad6967fac7cc3c1e
Author: Robert Knight <robertknight@gmail.com>
Date:   Tue Apr 15 11:06:52 2008 +0100

    Display a drop indicator arrow at the position where the tab will be dropped.

commit 137ade01d70d75d26f3c14624ec2c096c8c50eba
Author: Robert Knight <robertknight@gmail.com>
Date:   Tue Apr 15 10:01:28 2008 +0100

    Update detach view action state when moving tabs between windows.

commit 412c2d16844afda3f0427a5583d653c2214722fb
Author: Robert Knight <robertknight@gmail.com>
Date:   Tue Apr 15 09:56:37 2008 +0100

    Move mimetype definition to ViewProperties

commit dc31499351ef564cfe75c25124c3549b5dc75e16
Author: Robert Knight <robertknight@gmail.com>
Date:   Tue Apr 15 02:26:03 2008 +0100

    Hack around crash which can occur after a drag-and-drop tab move causes a view container to be destroyed, taking the QDrag object with it.  Fix this by setting the QDrag's parent object to 0 before calling removeView().  This leaks the QDrag however.

commit df057fd06988bcd2b4c0f21e1d746543e7cfe1c5
Author: Robert Knight <robertknight@gmail.com>
Date:   Tue Apr 15 02:24:21 2008 +0100

    Fix jumps based on uninitialized variables.

commit 864bfcc2e8c63e2c8a9b6e9c96bc4d90d3dacd7e
Author: Robert Knight <robertknight@gmail.com>
Date:   Tue Apr 15 00:20:12 2008 +0100

    Make the initiator of the tab drag event remove the view.  Change newViewRequest() -> moveViewRequest().  Do not delete the view if the tab is dropped onto another application which blindly accepts it.

commit b922858420d4b61ad2727c64bc885042280d65f4
Author: Robert Knight <robertknight@gmail.com>
Date:   Mon Apr 14 23:29:18 2008 +0100

    Add support for drag-and-drop moving of tabs between any two tab bars in the same process.

svn path=/trunk/KDE/kdebase/apps/konsole/; revision=797287