remove hack of loading workareas data engine in qml plugin
preparing to change QHash to QList in Workareas::Store

--this change is needed in order to support ordering
Workareas::Store change QHash to QList to support ordering
added Order field in the workareas data engine
implement QSortFilterProxyModel for tasks in desktop dialog

--dropped the old way to show tasks for specific workarea. I used
QSortFilterProxyModel that filters the tasks to show only the
relevant one.
Ordering Activities mechanism is almost here

--this commit enables all the ordering mechanism (limited
version, I have disabled the change activity
(running activity icon - locked state),
and instead to test ordering when you click in the
previous icon that activity becomes first.
IN NEXT COMMIT MUST BE RESTORED the functionality
created dragging appearance for activities
improved Dragging Interface for windows

--now it has a more structured code which is going to
be used also for DraggingInterfaceActivities
Simplify dragging for delegates and items

--WorkareaTaskDeleg was the first, the next big task here
is to try TaskPreviewDeleg which is a huge class
cleaned up a bit TaskPreviewDeleg

--one step at a time, I used containsMouse in TaskPreviewDeleg
instead of onEntered, onExited. Next Step is going to be to
use the new way of dragging in order to simplify more. And
final step, is going to be split TaskPreviewDeleg in three
classes, BasicTaskDeleg->TaskPreviewDeleg->DesktopTaskPreviewDeleg.
the first one is going to provide only basic elements.
the second is going to support previews and dragging.
the third is going to provide also scrolling support.
TaskPreviewDeleg moved to new dragging architecture, fixes

--TaskPreviewDeleg was cleaned a bit more. Now remains its
separation in three different classes
--An issue was found in counting windows in workareas, if
the workarea has more than 6 windows doesnot increment any
more windows number (maybe a new taskManager function can
help with this)
--The Filtered Task Model tried to be used with the Workareas
but the perfomance I think was dropped a lot
fix of not counting workareas correctly in a workarea

--when windows were more than 6 the windows number wasnt
increasing
Improved the Dragging Interface structure

--the dragging interface structure has been improved in
order to be easily used
improved delegates and dragging interface

--IMPORTANT Behavior Change: Double Click to
change Activity Name is dropped. It was simplified a bit,
in Locked Activities, clicking Activity Name changes to that
Activity, in Unlocked Activities, clicking enables editing
the Activity Name
--now dragging through the DraggingMouseArea is a lot more
organized
--improved Activity Delegate by using containsMouse instead
of onEntered, onExited
fixed a null pointer crash, bug in stopped activities
fix crash when clicking a window
fix wallpaper, use only activity default containment
created BasicTaskDeleg and used to CalibrationDialog
created ScrolledTaskPreview in order to break TaskPreview

--the best way to go would be ScrolledTaskPreview to use all
the same properties and functionality from TaskPreview but
I dont know if that's possible. A huge task here and very
dangerous in case something crashes...
started separation of TaskPreviewDeleg

--design decision is that because BasicTaskDeleg is
a simple one will be standalone but TaskPreviewDeleg
and ScrolledTaskPreview must share as much code as
possible for better future maintenance