AUI-1305 Creating a base class for viewing images

We've noticed that the carousel and the image viewer currently share a lot of behavior. This is refactoring this behavior into a single base class, and having these modules use it.
AUI-1305 Converting the carousel to extend from ImageViewerBase
AUI-1305 Refactoring slideshow behavior into aui-image-viewer-slideshow
AUI-1305 Converting ImageViewer to use ImageViewerSlideshow
AUI-1305 Creating aui-image-viewer-multiple
AUI-1305 Adding thumbnails to ImageViewer
AUI-1305 Source formatting
AUI-1305 Yogi loader regenerate
Lint
AUI-1305 Using absolute position for image-viewer-base controls
AUI-1305 Use valueFn to default value of HTML_PARSER attributes