Fixed NullPointerException

Image loads now
Merge branch 'Cameron' of https://github.com/cra5370/swen262-project into Cameron

Conflicts:
	build/classes/medicalimaging/ImageViewer$1.class
	build/classes/medicalimaging/ImageViewer$2.class
	build/classes/medicalimaging/ImageViewer.class
	src/medicalimaging/ImageViewer.java