Make "isWindowPrivate" property in wrapper for PrivateBrowsingUtils writable
(just like original one)
Move misplaced comment
dragEndHandler(): don't override this._dndPrivateNode, if it's already null
Slightly improve performance: don't check other hotkeys, if found matched one
Correctly ignore single char hotkeys in WYSIWYG editors
E.g. "V" hotkey should inserts "v" if focused node is editable and perform hotkey action otherwise