This is a big change, but should change nothing except the sizes of some
files and where they all are.
There are no more ext.multimediaViewer strings ANYWHERE, so let's keep
it that way. :)
Change-Id: Ic0892f5894700938bfa01f3f9bc8e5ab8276eb72
Keep modules in separate dirs, move images to their module dirs, and fix
up the module declarations so they still work.
Also moved viewer.svg into the root.
Bug: 56421
Change-Id: Ia84ddfd3b91c784c42d9ba243c5cfd46354f139f