Removed Viewer focusHandler/onCanvasFocus
Removed Viewer focusHandler/onCanvasFocus

Presumably, this was meant to manually scroll the viewer into view when it receives focus. This is already handled by browsers when tabbing to the viewer, so doing it explicitly isn't necessary, and it creates a negative user experience when clicking on a viewer to give it focus (as of #569).

shaunstanislaus/openseadragon,Iced-Tea/openseadragon,daverome/openseadragon,Iced-Tea/openseadragon,mcanthony/openseadragon,LarissaSmith/openseadragon,msalsbery/openseadragon,LarissaSmith/openseadragon,openseadragon/openseadragon,seanich/openseadragon,jmnetus/openseadragon,lidasong2014/openseadragon,shaunstanislaus/openseadragon,TMUND/openseadragon,jmnetus/openseadragon,goofwear/openseadragon,msalsbery/openseadragon,openseadragon/openseadragon,daverome/openseadragon,ricochet2200/openseadragon,seanich/openseadragon,goofwear/openseadragon,avandecreme/openseadragon,lidasong2014/openseadragon,rdlester/openseadragon,avandecreme/openseadragon,TMUND/openseadragon,mcanthony/openseadragon,rdlester/openseadragon,ricochet2200/openseadragon