new multiuser whiteboard icon and fixes for text object

...uebutton-client/branding/default/style/css/BBBDefault.css

...efault/style/css/assets/images/multiuserwhiteboardoff.png

...default/style/css/assets/images/multiuserwhiteboardon.png

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

...uebutton/modules/whiteboard/business/shapes/DrawObject.as

...uebutton/modules/whiteboard/business/shapes/TextObject.as

...bluebutton/modules/whiteboard/views/TextUpdateListener.as

...luebutton/modules/whiteboard/views/WhiteboardToolbar.mxml