Added "viewUpdated" event triggered whenever the view is updted
 Changes to be committed:
	modified:   src/iipmooviewer-2.0.js
	new file:   src/iipmooviewer-2.0.js~
	modified:   src/protocols/openslide_deepzoom.js
	new file:   src/protocols/openslide_deepzoom.js~
	modified:   src/touch.js