Code was cleaned.
Corrections in removing strokes.

Corrected adding items to group.
Corrected group creation.
Corrected adding items to scene - items shouldn't be added to itemsToRemove list because that list needs for cleaning undo stack.
Improved mechanism of removing "itemsToRemove".
Removed wrong deletion of mButtons list from UBGraphicsItemDelegate destructor because that buttons has Frame as parent.
Removed possible memory leak in UBBoardController::clearUndoStack. Some items was able not deleted.
tmpScene in cffReader not deletes now because ithas a proxy as parent.

Fixed some related issues.

Now coping creates a full copy of already created item. Copy has it's own content (like video, audio or folder) and stores original item properties (like locked, pos, size, freezed e.t.c.).

Improved mechansm of determination status of widgets - loading or error, or all is ok. Messages doesn't hides widget content.

The old code has to be removed and remaining bugs fixed.

This is not functional.

SANKORE-477 	Erasing an object with the keyboard

Fixed restoring of cursors at mouse release event on board.

It's icon is temporary.

Behavior implemented:
1. Can interact with all items without showing items frames (but ToolBar shows).
2. Cannot move items, but can drag images.
3. Selected items appears deselected when Play tool chosen.
4. Play tool don't requires selecting of item before interacts.
5. Cursor looks like tool icon in text and image widgets (should be the same in any others widgets, but now in w3c is not).

Fixed pages shuffling.
Fixed refreshing thumbnail of new added page.
Some code refactoring and optimizations.