- make switching presentation and page work

...button/modules/whiteboard/WhiteboardCanvasDisplayModel.as

...gbluebutton/modules/whiteboard/events/WhiteboardUpdate.as

...uebutton/modules/whiteboard/managers/WhiteboardManager.as

...luebutton/modules/whiteboard/maps/WhiteboardEventMap.mxml

...igbluebutton/modules/whiteboard/models/WhiteboardModel.as